2 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
3 * 2000 Wim Taymans <wim.taymans@chello.be>
4 * 2005 Wim Taymans <wim@fluendo.com>
6 * gstevent.c: GstEvent subsystem
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
18 * You should have received a copy of the GNU Library General Public
19 * License along with this library; if not, write to the
20 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
21 * Boston, MA 02111-1307, USA.
26 * @short_description: Structure describing events that are passed up and down
28 * @see_also: #GstPad, #GstElement
30 * The event class provides factory methods to construct events for sending
31 * and functions to query (parse) received events.
33 * Events are usually created with gst_event_new_*() which takes event-type
34 * specific parameters as arguments.
35 * To send an event application will usually use gst_element_send_event() and
36 * elements will use gst_pad_send_event() or gst_pad_push_event().
37 * The event should be unreffed with gst_event_unref() if it has not been sent.
39 * Events that have been received can be parsed with their respective
40 * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
42 * Events are passed between elements in parallel to the data stream. Some events
43 * are serialized with buffers, others are not. Some events only travel downstream,
44 * others only upstream. Some events can travel both upstream and downstream.
46 * The events are used to signal special conditions in the datastream such as
47 * EOS (end of stream) or the start of a new stream-segment.
48 * Events are also used to flush the pipeline of any pending data.
50 * Most of the event API is used inside plugins. Applications usually only
51 * construct and use seek events.
52 * To do that gst_event_new_seek() is used to create a seek event. It takes
53 * the needed parameters to specify seeking time and mode.
55 * <title>performing a seek on a pipeline</title>
60 * // construct a seek event to play the media from second 2 to 5, flush
61 * // the pipeline to decrease latency.
62 * event = gst_event_new_seek (1.0,
64 * GST_SEEK_FLAG_FLUSH,
65 * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
66 * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
68 * result = gst_element_send_event (pipeline, event);
70 * g_warning ("seek failed");
75 * Last reviewed on 2012-03-28 (0.11.3)
79 #include "gst_private.h"
80 #include <string.h> /* memcpy */
84 #include "gstenumtypes.h"
89 GType _gst_event_type = 0;
95 GstStructure *structure;
98 #define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
107 static GstEventQuarks event_quarks[] = {
108 {GST_EVENT_UNKNOWN, "unknown", 0},
109 {GST_EVENT_FLUSH_START, "flush-start", 0},
110 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
111 {GST_EVENT_STREAM_START, "stream-start", 0},
112 {GST_EVENT_CAPS, "caps", 0},
113 {GST_EVENT_STREAM_CONFIG, "stream-config", 0},
114 {GST_EVENT_SEGMENT, "segment", 0},
115 {GST_EVENT_TAG, "tag", 0},
116 {GST_EVENT_TOC, "toc", 0},
117 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
118 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
119 {GST_EVENT_EOS, "eos", 0},
120 {GST_EVENT_SEGMENT_DONE, "segment-done", 0},
121 {GST_EVENT_GAP, "gap", 0},
122 {GST_EVENT_QOS, "qos", 0},
123 {GST_EVENT_SEEK, "seek", 0},
124 {GST_EVENT_NAVIGATION, "navigation", 0},
125 {GST_EVENT_LATENCY, "latency", 0},
126 {GST_EVENT_STEP, "step", 0},
127 {GST_EVENT_RECONFIGURE, "reconfigure", 0},
128 {GST_EVENT_TOC_SELECT, "toc-select", 0},
129 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
130 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
131 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
132 {GST_EVENT_CUSTOM_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
133 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
134 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
139 GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
142 _priv_gst_event_initialize (void)
146 _gst_event_type = gst_event_get_type ();
148 g_type_class_ref (gst_seek_flags_get_type ());
149 g_type_class_ref (gst_seek_type_get_type ());
151 for (i = 0; event_quarks[i].name; i++) {
152 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
157 * gst_event_type_get_name:
158 * @type: the event type
160 * Get a printable name for the given event type. Do not modify or free.
162 * Returns: a reference to the static name of the event.
165 gst_event_type_get_name (GstEventType type)
169 for (i = 0; event_quarks[i].name; i++) {
170 if (type == event_quarks[i].type)
171 return event_quarks[i].name;
177 * gst_event_type_to_quark:
178 * @type: the event type
180 * Get the unique quark for the given event type.
182 * Returns: the quark associated with the event type
185 gst_event_type_to_quark (GstEventType type)
189 for (i = 0; event_quarks[i].name; i++) {
190 if (type == event_quarks[i].type)
191 return event_quarks[i].quark;
197 * gst_event_type_get_flags:
198 * @type: a #GstEventType
200 * Gets the #GstEventTypeFlags associated with @type.
202 * Returns: a #GstEventTypeFlags.
205 gst_event_type_get_flags (GstEventType type)
207 GstEventTypeFlags ret;
209 ret = type & ((1 << GST_EVENT_NUM_SHIFT) - 1);
215 _gst_event_free (GstEvent * event)
219 g_return_if_fail (event != NULL);
220 g_return_if_fail (GST_IS_EVENT (event));
222 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
223 GST_EVENT_TYPE_NAME (event));
225 s = GST_EVENT_STRUCTURE (event);
228 gst_structure_set_parent_refcount (s, NULL);
229 gst_structure_free (s);
232 g_slice_free1 (sizeof (GstEventImpl), event);
235 static void gst_event_init (GstEventImpl * event, GstEventType type);
238 _gst_event_copy (GstEvent * event)
243 copy = g_slice_new0 (GstEventImpl);
245 gst_event_init (copy, GST_EVENT_TYPE (event));
247 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
248 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
250 s = GST_EVENT_STRUCTURE (event);
252 GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
253 gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
254 ©->event.mini_object.refcount);
256 GST_EVENT_STRUCTURE (copy) = NULL;
258 return GST_EVENT_CAST (copy);
262 gst_event_init (GstEventImpl * event, GstEventType type)
264 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
265 (GstMiniObjectCopyFunction) _gst_event_copy, NULL,
266 (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, type);
312 GST_EVENT_STRUCTURE (event) = structure;
314 return GST_EVENT_CAST (event);
319 g_slice_free1 (sizeof (GstEventImpl), 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.
389 gst_event_has_name (GstEvent * event, const gchar * name)
391 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
393 if (GST_EVENT_STRUCTURE (event) == NULL)
396 return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
400 * gst_event_get_seqnum:
401 * @event: A #GstEvent.
403 * Retrieve the sequence number of a event.
405 * Events have ever-incrementing sequence numbers, which may also be set
406 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
407 * indicate that a event corresponds to some other set of events or messages,
408 * for example an EOS event corresponding to a SEEK event. It is considered good
409 * practice to make this correspondence when possible, though it is not
412 * Note that events and messages share the same sequence number incrementor;
413 * two events or messages will never have the same sequence number unless
414 * that correspondence was made explicitly.
416 * Returns: The event's sequence number.
421 gst_event_get_seqnum (GstEvent * event)
423 g_return_val_if_fail (GST_IS_EVENT (event), -1);
425 return GST_EVENT_SEQNUM (event);
429 * gst_event_set_seqnum:
430 * @event: A #GstEvent.
431 * @seqnum: A sequence number.
433 * Set the sequence number of a event.
435 * This function might be called by the creator of a event to indicate that the
436 * event relates to other events or messages. See gst_event_get_seqnum() for
442 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
444 g_return_if_fail (GST_IS_EVENT (event));
446 GST_EVENT_SEQNUM (event) = seqnum;
450 * gst_event_new_flush_start:
452 * Allocate a new flush start event. The flush start event can be sent
453 * upstream and downstream and travels out-of-bounds with the dataflow.
455 * It marks pads as being flushing and will make them return
456 * #GST_FLOW_FLUSHING when used for data flow with gst_pad_push(),
457 * gst_pad_chain(), gst_pad_get_range() and gst_pad_pull_range().
458 * Any event (except a #GST_EVENT_FLUSH_STOP) received
459 * on a flushing pad will return %FALSE immediately.
461 * Elements should unlock any blocking functions and exit their streaming
462 * functions as fast as possible when this event is received.
464 * This event is typically generated after a seek to flush out all queued data
465 * in the pipeline so that the new media is played as soon as possible.
467 * Returns: (transfer full): a new flush start event.
470 gst_event_new_flush_start (void)
472 return gst_event_new_custom (GST_EVENT_FLUSH_START, NULL);
476 * gst_event_new_flush_stop:
477 * @reset_time: if time should be reset
479 * Allocate a new flush stop event. The flush stop event can be sent
480 * upstream and downstream and travels serialized with the dataflow.
481 * It is typically sent after sending a FLUSH_START event to make the
482 * pads accept data again.
484 * Elements can process this event synchronized with the dataflow since
485 * the preceeding FLUSH_START event stopped the dataflow.
487 * This event is typically generated to complete a seek and to resume
490 * Returns: (transfer full): a new flush stop event.
493 gst_event_new_flush_stop (gboolean reset_time)
497 GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
499 event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
500 gst_structure_new_id (GST_QUARK (EVENT_FLUSH_STOP),
501 GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
507 * gst_event_parse_flush_stop:
508 * @event: The event to parse
509 * @reset_time: (out): if time should be reset
511 * Parse the FLUSH_STOP event and retrieve the @reset_time member.
514 gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
516 GstStructure *structure;
518 g_return_if_fail (GST_IS_EVENT (event));
519 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
521 structure = GST_EVENT_STRUCTURE (event);
522 if (G_LIKELY (reset_time))
524 g_value_get_boolean (gst_structure_id_get_value (structure,
525 GST_QUARK (RESET_TIME)));
531 * Create a new EOS event. The eos event can only travel downstream
532 * synchronized with the buffer flow. Elements that receive the EOS
533 * event on a pad can return #GST_FLOW_EOS as a #GstFlowReturn
534 * when data after the EOS event arrives.
536 * The EOS event will travel down to the sink elements in the pipeline
537 * which will then post the #GST_MESSAGE_EOS on the bus after they have
538 * finished playing any buffered data.
540 * When all sinks have posted an EOS message, an EOS message is
541 * forwarded to the application.
543 * The EOS event itself will not cause any state transitions of the pipeline.
545 * Returns: (transfer full): the new EOS event.
548 gst_event_new_eos (void)
550 return gst_event_new_custom (GST_EVENT_EOS, NULL);
555 * @timestamp: the start time (pts) of the gap
556 * @duration: the duration of the gap
558 * Create a new GAP event. A gap event can be thought of as conceptually
559 * equivalent to a buffer to signal that there is no data for a certain
560 * amount of time. This is useful to signal a gap to downstream elements
561 * which may wait for data, such as muxers or mixers or overlays, especially
562 * for sparse streams such as subtitle streams.
564 * Returns: (transfer full): the new GAP event.
567 gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
571 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
572 g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (duration), NULL);
574 GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
575 "%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
576 GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
577 GST_TIME_ARGS (duration));
579 event = gst_event_new_custom (GST_EVENT_GAP,
580 gst_structure_new_id (GST_QUARK (EVENT_GAP),
581 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
582 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
588 * gst_event_parse_gap:
589 * @event: a #GstEvent of type #GST_EVENT_GAP
590 * @timestamp: (out) (allow-none): location where to store the
591 * start time (pts) of the gap, or %NULL
592 * @duration: (out) (allow-none): location where to store the duration of
595 * Extract timestamp and duration from a new GAP event.
598 gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
599 GstClockTime * duration)
601 GstStructure *structure;
603 g_return_if_fail (GST_IS_EVENT (event));
604 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
606 structure = GST_EVENT_STRUCTURE (event);
607 gst_structure_id_get (structure,
608 GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
609 GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
613 * gst_event_new_caps:
614 * @caps: (transfer none): a #GstCaps
616 * Create a new CAPS event for @caps. The caps event can only travel downstream
617 * synchronized with the buffer flow and contains the format of the buffers
618 * that will follow after the event.
620 * Returns: (transfer full): the new CAPS event.
623 gst_event_new_caps (GstCaps * caps)
627 g_return_val_if_fail (caps != NULL, NULL);
628 g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
630 GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
632 event = gst_event_new_custom (GST_EVENT_CAPS,
633 gst_structure_new_id (GST_QUARK (EVENT_CAPS),
634 GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
640 * gst_event_parse_caps:
641 * @event: The event to parse
642 * @caps: (out) (transfer none): A pointer to the caps
644 * Get the caps from @event. The caps remains valid as long as @event remains
648 gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
650 GstStructure *structure;
652 g_return_if_fail (GST_IS_EVENT (event));
653 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
655 structure = GST_EVENT_STRUCTURE (event);
658 g_value_get_boxed (gst_structure_id_get_value (structure,
663 * gst_event_new_stream_config:
664 * @flags: the stream config flags
666 * Create a new STREAM CONFIG event. The stream config event travels
667 * downstream synchronized with the buffer flow and contains stream
668 * configuration information for the stream, such as stream-headers
669 * or setup-data. It is optional and should be sent after the CAPS
672 * Returns: (transfer full): the new STREAM CONFIG event.
675 gst_event_new_stream_config (GstStreamConfigFlags flags)
679 GST_CAT_INFO (GST_CAT_EVENT, "creating stream info event, flags=0x%x", flags);
681 event = gst_event_new_custom (GST_EVENT_STREAM_CONFIG,
682 gst_structure_new_id (GST_QUARK (EVENT_STREAM_CONFIG),
683 GST_QUARK (FLAGS), GST_TYPE_STREAM_CONFIG_FLAGS, flags, NULL));
689 * gst_event_parse_stream_config:
690 * @event: The event to parse
691 * @flags: (out): a pointer to a variable to store the stream config flags
693 * Get the stream config flags from @event.
696 gst_event_parse_stream_config (GstEvent * event, GstStreamConfigFlags * flags)
698 GstStructure *structure;
700 g_return_if_fail (GST_IS_EVENT (event));
701 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
703 structure = GST_EVENT_STRUCTURE (event);
704 if (G_LIKELY (flags != NULL)) {
706 g_value_get_enum (gst_structure_id_get_value (structure,
712 * gst_event_set_stream_config_setup_data:
713 * @event: a stream config event
714 * @buf: a #GstBuffer with setup data
716 * Set setup data on the stream info event to signal out of bound setup data
717 * to downstream elements. Unlike stream headers, setup data contains data
718 * that is required to interpret the data stream, but is not valid as-is
719 * inside the data stream and thus can't just be prepended to or inserted
720 * into the data stream.
723 gst_event_set_stream_config_setup_data (GstEvent * event, GstBuffer * buf)
727 g_return_if_fail (GST_IS_EVENT (event));
728 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
729 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
731 s = GST_EVENT_STRUCTURE (event);
732 gst_structure_id_set (s, GST_QUARK (SETUP_DATA), GST_TYPE_BUFFER, buf, NULL);
736 * gst_event_parse_stream_config_setup_data:
737 * @event: a stream config event
738 * @buf: (out) (transfer none): location where to store the #GstBuffer with setup data
740 * Extracts the setup data buffer from the stream info event. Will store
741 * %NULL in @buf if the event contains no setup data. The buffer returned
742 * will remain valid as long as @event remains valid. The caller should
743 * acquire a reference to to @buf if needed.
745 * Returns: TRUE if @event contained setup data and @buf has been set,
749 gst_event_parse_stream_config_setup_data (GstEvent * event, GstBuffer ** buf)
754 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
755 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG,
757 g_return_val_if_fail (buf != NULL, FALSE);
759 s = GST_EVENT_STRUCTURE (event);
760 val = gst_structure_id_get_value (s, GST_QUARK (SETUP_DATA));
762 *buf = g_value_get_boxed (val);
766 return (*buf != NULL);
770 * gst_event_add_stream_config_header:
771 * @event: a stream config event
772 * @buf: a #GstBuffer with stream header data
774 * Adds a stream header to the stream info event to signal stream headers to
775 * to downstream elements such as multifilesink, tcpserversink etc. Stream
776 * headers can be and should usually be prepended to the data stream at any
777 * point in the stream (which requires a streamable format), e.g. to a new
778 * client connecting, or when starting a new file segment. stream header
779 * buffers will all be used together in the order they were added to the
780 * stream config event. Stream headers are sent as buffers at the beginning
781 * of the data flow in addition to the stream config event. Elements that
782 * care about stream headers need to make sure that they don't insert or
783 * interpret these header buffers twice if they interpret them.
786 gst_event_add_stream_config_header (GstEvent * event, GstBuffer * buf)
789 GValue buf_val = { 0, };
792 g_return_if_fail (GST_IS_EVENT (event));
793 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG);
794 g_return_if_fail (GST_IS_BUFFER (buf) && gst_buffer_get_size (buf) > 0);
796 g_value_init (&buf_val, GST_TYPE_BUFFER);
797 g_value_set_boxed (&buf_val, buf);
799 s = GST_EVENT_STRUCTURE (event);
800 val = (GValue *) gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
802 GValue new_array = { 0, };
804 g_value_init (&new_array, GST_TYPE_ARRAY);
805 gst_value_array_append_value (&new_array, &buf_val);
806 gst_structure_id_take_value (s, GST_QUARK (STREAM_HEADERS), &new_array);
808 gst_value_array_append_value (val, &buf_val);
810 g_value_unset (&buf_val);
814 * gst_event_get_n_stream_config_headers:
815 * @event: a stream config event
817 * Extract the number of stream header buffers.
819 * Returns: the number of stream header buffers attached to the stream info
823 gst_event_get_n_stream_config_headers (GstEvent * event)
829 g_return_val_if_fail (GST_IS_EVENT (event), 0);
830 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG, 0);
832 s = GST_EVENT_STRUCTURE (event);
833 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
836 num = gst_value_array_get_size (val);
842 * gst_event_parse_nth_stream_config_header:
843 * @event: a stream config event
844 * @index: number of the stream header to retrieve
845 * @buf: (out) (transfer none): location where to store the n-th stream
848 * Retrieves the n-th stream header buffer attached to the stream config
849 * event and stores it in @buf. Will store %NULL in @buf if there is no such
852 * Returns: TRUE if @event contained a stream header at @index and @buf has
853 * been set, otherwise FALSE.
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_val_if_fail (GST_IS_EVENT (event), FALSE);
864 g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_CONFIG,
866 g_return_val_if_fail (buf != NULL, FALSE);
868 s = GST_EVENT_STRUCTURE (event);
869 val = gst_structure_id_get_value (s, GST_QUARK (STREAM_HEADERS));
872 buf_val = gst_value_array_get_value (val, index);
874 ret = g_value_get_boxed (buf_val);
878 return (ret != NULL);
882 * gst_event_new_segment:
883 * @segment: (transfer none): a #GstSegment
885 * Create a new SEGMENT event for @segment. The segment event can only travel
886 * downstream synchronized with the buffer flow and contains timing information
887 * and playback properties for the buffers that will follow.
889 * The newsegment event marks the range of buffers to be processed. All
890 * data not within the segment range is not to be processed. This can be
891 * used intelligently by plugins to apply more efficient methods of skipping
892 * unneeded data. The valid range is expressed with the @start and @stop
895 * The time value of the segment is used in conjunction with the start
896 * value to convert the buffer timestamps into the stream time. This is
897 * usually done in sinks to report the current stream_time.
898 * @time represents the stream_time of a buffer carrying a timestamp of
899 * @start. @time cannot be -1.
901 * @start cannot be -1, @stop can be -1. If there
902 * is a valid @stop given, it must be greater or equal the @start, including
903 * when the indicated playback @rate is < 0.
905 * The @applied_rate value provides information about any rate adjustment that
906 * has already been made to the timestamps and content on the buffers of the
907 * stream. (@rate * @applied_rate) should always equal the rate that has been
908 * requested for playback. For example, if an element has an input segment
909 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
910 * incoming timestamps and buffer content by half and output a newsegment event
911 * with @rate of 1.0 and @applied_rate of 2.0
913 * After a newsegment event, the buffer stream time is calculated with:
915 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
917 * Returns: (transfer full): the new SEGMENT event.
920 gst_event_new_segment (const GstSegment * segment)
924 g_return_val_if_fail (segment != NULL, NULL);
925 g_return_val_if_fail (segment->rate != 0.0, NULL);
926 g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
927 g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
929 GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
932 event = gst_event_new_custom (GST_EVENT_SEGMENT,
933 gst_structure_new_id (GST_QUARK (EVENT_SEGMENT),
934 GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
940 * gst_event_parse_segment:
941 * @event: The event to parse
942 * @segment: (out) (transfer none): a pointer to a #GstSegment
944 * Parses a segment @event and stores the result in the given @segment location.
945 * @segment remains valid only until the @event is freed. Don't modify the segment
946 * and make a copy if you want to modify it or store it for later use.
949 gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
951 GstStructure *structure;
953 g_return_if_fail (GST_IS_EVENT (event));
954 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
957 structure = GST_EVENT_STRUCTURE (event);
958 *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
959 GST_QUARK (SEGMENT)));
964 * gst_event_copy_segment:
965 * @event: The event to parse
966 * @segment: a pointer to a #GstSegment
968 * Parses a segment @event and copies the #GstSegment into the location
972 gst_event_copy_segment (GstEvent * event, GstSegment * segment)
974 const GstSegment *src;
976 g_return_if_fail (GST_IS_EVENT (event));
977 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
980 gst_event_parse_segment (event, &src);
981 gst_segment_copy_into (src, segment);
987 * @taglist: (transfer full): metadata list. The event will take ownership
990 * Generates a metadata tag event from the given @taglist.
992 * The scope of the taglist specifies if the taglist applies to the
993 * complete medium or only to this specific stream. As the tag event
994 * is a sticky event, elements should merge tags received from
995 * upstream with a given scope with their own tags with the same
996 * scope and create a new tag event from it.
998 * Returns: (transfer full): a new #GstEvent
1001 gst_event_new_tag (GstTagList * taglist)
1004 GValue val = G_VALUE_INIT;
1005 const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
1007 g_return_val_if_fail (taglist != NULL, NULL);
1009 s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
1010 g_value_init (&val, GST_TYPE_TAG_LIST);
1011 g_value_take_boxed (&val, taglist);
1012 gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
1013 return gst_event_new_custom (GST_EVENT_TAG, s);
1017 * gst_event_parse_tag:
1018 * @event: a tag event
1019 * @taglist: (out) (transfer none): pointer to metadata list
1021 * Parses a tag @event and stores the results in the given @taglist location.
1022 * No reference to the taglist will be returned, it remains valid only until
1023 * the @event is freed. Don't modify or free the taglist, make a copy if you
1024 * want to modify it or store it for later use.
1027 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
1031 g_return_if_fail (GST_IS_EVENT (event));
1032 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
1034 val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
1035 GST_QUARK (TAGLIST));
1038 *taglist = (GstTagList *) g_value_get_boxed (val);
1041 /* buffersize event */
1043 * gst_event_new_buffer_size:
1044 * @format: buffer format
1045 * @minsize: minimum buffer size
1046 * @maxsize: maximum buffer size
1047 * @async: thread behavior
1049 * Create a new buffersize event. The event is sent downstream and notifies
1050 * elements that they should provide a buffer of the specified dimensions.
1052 * When the @async flag is set, a thread boundary is preferred.
1054 * Returns: (transfer full): a new #GstEvent
1057 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
1058 gint64 maxsize, gboolean async)
1061 GstStructure *structure;
1063 GST_CAT_INFO (GST_CAT_EVENT,
1064 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
1065 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
1066 minsize, maxsize, async);
1068 structure = gst_structure_new_id (GST_QUARK (EVENT_BUFFER_SIZE),
1069 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1070 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
1071 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
1072 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
1073 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
1079 * gst_event_parse_buffer_size:
1080 * @event: The event to query
1081 * @format: (out): A pointer to store the format in
1082 * @minsize: (out): A pointer to store the minsize in
1083 * @maxsize: (out): A pointer to store the maxsize in
1084 * @async: (out): A pointer to store the async-flag in
1086 * Get the format, minsize, maxsize and async-flag in the buffersize event.
1089 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
1090 gint64 * minsize, gint64 * maxsize, gboolean * async)
1092 const GstStructure *structure;
1094 g_return_if_fail (GST_IS_EVENT (event));
1095 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
1097 structure = GST_EVENT_STRUCTURE (event);
1099 *format = (GstFormat)
1100 g_value_get_enum (gst_structure_id_get_value (structure,
1101 GST_QUARK (FORMAT)));
1104 g_value_get_int64 (gst_structure_id_get_value (structure,
1105 GST_QUARK (MINSIZE)));
1108 g_value_get_int64 (gst_structure_id_get_value (structure,
1109 GST_QUARK (MAXSIZE)));
1112 g_value_get_boolean (gst_structure_id_get_value (structure,
1113 GST_QUARK (ASYNC)));
1117 * gst_event_new_qos:
1118 * @type: the QoS type
1119 * @proportion: the proportion of the qos message
1120 * @diff: The time difference of the last Clock sync
1121 * @timestamp: The timestamp of the buffer
1123 * Allocate a new qos event with the given values.
1124 * The QOS event is generated in an element that wants an upstream
1125 * element to either reduce or increase its rate because of
1126 * high/low CPU load or other resource usage such as network performance or
1127 * throttling. Typically sinks generate these events for each buffer
1130 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
1131 * used when a buffer arrived in time or when the sink cannot keep up with
1132 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
1133 * receiving buffers fast enough and thus has to drop late buffers.
1134 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
1135 * by the application, for example to reduce power consumption.
1137 * @proportion indicates the real-time performance of the streaming in the
1138 * element that generated the QoS event (usually the sink). The value is
1139 * generally computed based on more long term statistics about the streams
1140 * timestamps compared to the clock.
1141 * A value < 1.0 indicates that the upstream element is producing data faster
1142 * than real-time. A value > 1.0 indicates that the upstream element is not
1143 * producing data fast enough. 1.0 is the ideal @proportion value. The
1144 * proportion value can safely be used to lower or increase the quality of
1147 * @diff is the difference against the clock in running time of the last
1148 * buffer that caused the element to generate the QOS event. A negative value
1149 * means that the buffer with @timestamp arrived in time. A positive value
1150 * indicates how late the buffer with @timestamp was. When throttling is
1151 * enabled, @diff will be set to the requested throttling interval.
1153 * @timestamp is the timestamp of the last buffer that cause the element
1154 * to generate the QOS event. It is expressed in running time and thus an ever
1157 * The upstream element can use the @diff and @timestamp values to decide
1158 * whether to process more buffers. For possitive @diff, all buffers with
1159 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
1160 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
1161 * result smaller than 0 is not allowed.
1163 * The application can use general event probes to intercept the QoS
1164 * event and implement custom application specific QoS handling.
1166 * Returns: (transfer full): a new QOS event.
1169 gst_event_new_qos (GstQOSType type, gdouble proportion,
1170 GstClockTimeDiff diff, GstClockTime timestamp)
1173 GstStructure *structure;
1175 /* diff must be positive or timestamp + diff must be positive */
1176 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
1178 GST_CAT_LOG (GST_CAT_EVENT,
1179 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
1180 ", timestamp %" GST_TIME_FORMAT, type, proportion,
1181 diff, GST_TIME_ARGS (timestamp));
1183 structure = gst_structure_new_id (GST_QUARK (EVENT_QOS),
1184 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
1185 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
1186 GST_QUARK (DIFF), G_TYPE_INT64, diff,
1187 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
1188 event = gst_event_new_custom (GST_EVENT_QOS, structure);
1194 * gst_event_parse_qos:
1195 * @event: The event to query
1196 * @type: (out): A pointer to store the QoS type in
1197 * @proportion: (out): A pointer to store the proportion in
1198 * @diff: (out): A pointer to store the diff in
1199 * @timestamp: (out): A pointer to store the timestamp in
1201 * Get the type, proportion, diff and timestamp in the qos event. See
1202 * gst_event_new_qos() for more information about the different QoS values.
1205 gst_event_parse_qos (GstEvent * event, GstQOSType * type,
1206 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
1208 const GstStructure *structure;
1210 g_return_if_fail (GST_IS_EVENT (event));
1211 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
1213 structure = GST_EVENT_STRUCTURE (event);
1215 *type = (GstQOSType)
1216 g_value_get_enum (gst_structure_id_get_value (structure,
1220 g_value_get_double (gst_structure_id_get_value (structure,
1221 GST_QUARK (PROPORTION)));
1224 g_value_get_int64 (gst_structure_id_get_value (structure,
1228 g_value_get_uint64 (gst_structure_id_get_value (structure,
1229 GST_QUARK (TIMESTAMP)));
1233 * gst_event_new_seek:
1234 * @rate: The new playback rate
1235 * @format: The format of the seek values
1236 * @flags: The optional seek flags
1237 * @start_type: The type and flags for the new start position
1238 * @start: The value of the new start position
1239 * @stop_type: The type and flags for the new stop position
1240 * @stop: The value of the new stop position
1242 * Allocate a new seek event with the given parameters.
1244 * The seek event configures playback of the pipeline between @start to @stop
1245 * at the speed given in @rate, also called a playback segment.
1246 * The @start and @stop values are expressed in @format.
1248 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
1249 * Negatives values means backwards playback. A value of 0.0 for the
1250 * rate is not allowed and should be accomplished instead by PAUSING the
1253 * A pipeline has a default playback segment configured with a start
1254 * position of 0, a stop position of -1 and a rate of 1.0. The currently
1255 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
1257 * @start_type and @stop_type specify how to adjust the currently configured
1258 * start and stop fields in playback segment. Adjustments can be made relative
1259 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
1260 * means that the position should not be updated.
1262 * When the rate is positive and @start has been updated, playback will start
1263 * from the newly configured start position.
1265 * For negative rates, playback will start from the newly configured stop
1266 * position (if any). If the stop position is updated, it must be different from
1267 * -1 (#GST_CLOCK_TIME_NONE) for negative rates.
1269 * It is not possible to seek relative to the current playback position, to do
1270 * this, PAUSE the pipeline, query the current playback position with
1271 * #GST_QUERY_POSITION and update the playback segment current position with a
1272 * #GST_SEEK_TYPE_SET to the desired position.
1274 * Returns: (transfer full): a new seek event.
1277 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1278 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1281 GstStructure *structure;
1283 g_return_val_if_fail (rate != 0.0, NULL);
1285 if (format == GST_FORMAT_TIME) {
1286 GST_CAT_INFO (GST_CAT_EVENT,
1287 "creating seek rate %lf, format TIME, flags %d, "
1288 "start_type %d, start %" GST_TIME_FORMAT ", "
1289 "stop_type %d, stop %" GST_TIME_FORMAT,
1290 rate, flags, start_type, GST_TIME_ARGS (start),
1291 stop_type, GST_TIME_ARGS (stop));
1293 GST_CAT_INFO (GST_CAT_EVENT,
1294 "creating seek rate %lf, format %s, flags %d, "
1295 "start_type %d, start %" G_GINT64_FORMAT ", "
1296 "stop_type %d, stop %" G_GINT64_FORMAT,
1297 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1301 structure = gst_structure_new_id (GST_QUARK (EVENT_SEEK),
1302 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1303 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1304 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1305 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1306 GST_QUARK (CUR), G_TYPE_INT64, start,
1307 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1308 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1309 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1315 * gst_event_parse_seek:
1316 * @event: a seek event
1317 * @rate: (out): result location for the rate
1318 * @format: (out): result location for the stream format
1319 * @flags: (out): result location for the #GstSeekFlags
1320 * @start_type: (out): result location for the #GstSeekType of the start position
1321 * @start: (out): result location for the start postion expressed in @format
1322 * @stop_type: (out): result location for the #GstSeekType of the stop position
1323 * @stop: (out): result location for the stop postion expressed in @format
1325 * Parses a seek @event and stores the results in the given result locations.
1328 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1329 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1330 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1332 const GstStructure *structure;
1334 g_return_if_fail (GST_IS_EVENT (event));
1335 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1337 structure = GST_EVENT_STRUCTURE (event);
1340 g_value_get_double (gst_structure_id_get_value (structure,
1343 *format = (GstFormat)
1344 g_value_get_enum (gst_structure_id_get_value (structure,
1345 GST_QUARK (FORMAT)));
1347 *flags = (GstSeekFlags)
1348 g_value_get_flags (gst_structure_id_get_value (structure,
1349 GST_QUARK (FLAGS)));
1351 *start_type = (GstSeekType)
1352 g_value_get_enum (gst_structure_id_get_value (structure,
1353 GST_QUARK (CUR_TYPE)));
1356 g_value_get_int64 (gst_structure_id_get_value (structure,
1359 *stop_type = (GstSeekType)
1360 g_value_get_enum (gst_structure_id_get_value (structure,
1361 GST_QUARK (STOP_TYPE)));
1364 g_value_get_int64 (gst_structure_id_get_value (structure,
1369 * gst_event_new_navigation:
1370 * @structure: (transfer full): description of the event. The event will take
1371 * ownership of the structure.
1373 * Create a new navigation event from the given description.
1375 * Returns: (transfer full): a new #GstEvent
1378 gst_event_new_navigation (GstStructure * structure)
1380 g_return_val_if_fail (structure != NULL, NULL);
1382 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1386 * gst_event_new_latency:
1387 * @latency: the new latency value
1389 * Create a new latency event. The event is sent upstream from the sinks and
1390 * notifies elements that they should add an additional @latency to the
1391 * running time before synchronising against the clock.
1393 * The latency is mostly used in live sinks and is always expressed in
1396 * Returns: (transfer full): a new #GstEvent
1399 gst_event_new_latency (GstClockTime latency)
1402 GstStructure *structure;
1404 GST_CAT_INFO (GST_CAT_EVENT,
1405 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1407 structure = gst_structure_new_id (GST_QUARK (EVENT_LATENCY),
1408 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1409 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1415 * gst_event_parse_latency:
1416 * @event: The event to query
1417 * @latency: (out): A pointer to store the latency in.
1419 * Get the latency in the latency event.
1422 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1424 g_return_if_fail (GST_IS_EVENT (event));
1425 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1429 g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
1430 (event), GST_QUARK (LATENCY)));
1434 * gst_event_new_step:
1435 * @format: the format of @amount
1436 * @amount: the amount of data to step
1437 * @rate: the step rate
1438 * @flush: flushing steps
1439 * @intermediate: intermediate steps
1441 * Create a new step event. The purpose of the step event is to instruct a sink
1442 * to skip @amount (expressed in @format) of media. It can be used to implement
1443 * stepping through the video frame by frame or for doing fast trick modes.
1445 * A rate of <= 0.0 is not allowed. Pause the pipeline, for the effect of rate
1446 * = 0.0 or first reverse the direction of playback using a seek event to get
1447 * the same effect as rate < 0.0.
1449 * The @flush flag will clear any pending data in the pipeline before starting
1450 * the step operation.
1452 * The @intermediate flag instructs the pipeline that this step operation is
1453 * part of a larger step operation.
1455 * Returns: (transfer full): a new #GstEvent
1458 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1459 gboolean flush, gboolean intermediate)
1462 GstStructure *structure;
1464 g_return_val_if_fail (rate > 0.0, NULL);
1466 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1468 structure = gst_structure_new_id (GST_QUARK (EVENT_STEP),
1469 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1470 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1471 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1472 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1473 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1474 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1480 * gst_event_parse_step:
1481 * @event: The event to query
1482 * @format: (out) (allow-none): a pointer to store the format in
1483 * @amount: (out) (allow-none): a pointer to store the amount in
1484 * @rate: (out) (allow-none): a pointer to store the rate in
1485 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1486 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1489 * Parse the step event.
1492 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1493 gdouble * rate, gboolean * flush, gboolean * intermediate)
1495 const GstStructure *structure;
1497 g_return_if_fail (GST_IS_EVENT (event));
1498 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1500 structure = GST_EVENT_STRUCTURE (event);
1503 (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
1504 GST_QUARK (FORMAT)));
1506 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1507 GST_QUARK (AMOUNT)));
1509 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1512 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1513 GST_QUARK (FLUSH)));
1515 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1516 GST_QUARK (INTERMEDIATE)));
1520 * gst_event_new_reconfigure:
1522 * Create a new reconfigure event. The purpose of the reconfingure event is
1523 * to travel upstream and make elements renegotiate their caps or reconfigure
1524 * their buffer pools. This is useful when changing properties on elements
1525 * or changing the topology of the pipeline.
1527 * Returns: (transfer full): a new #GstEvent
1530 gst_event_new_reconfigure (void)
1534 GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
1536 event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
1542 * gst_event_new_sink_message:
1543 * @name: a name for the event
1544 * @msg: (transfer none): the #GstMessage to be posted
1546 * Create a new sink-message event. The purpose of the sink-message event is
1547 * to instruct a sink to post the message contained in the event synchronized
1550 * @name is used to store multiple sticky events on one pad.
1552 * Returns: (transfer full): a new #GstEvent
1554 /* FIXME 0.11: take ownership of msg for consistency? */
1556 gst_event_new_sink_message (const gchar * name, GstMessage * msg)
1559 GstStructure *structure;
1561 g_return_val_if_fail (msg != NULL, NULL);
1563 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1565 structure = gst_structure_new_id (g_quark_from_string (name),
1566 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1567 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1573 * gst_event_parse_sink_message:
1574 * @event: The event to query
1575 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1577 * Parse the sink-message event. Unref @msg after usage.
1580 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1582 const GstStructure *structure;
1584 g_return_if_fail (GST_IS_EVENT (event));
1585 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1587 structure = GST_EVENT_STRUCTURE (event);
1590 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1591 (structure, GST_QUARK (MESSAGE))));
1595 * gst_event_new_stream_start:
1597 * Create a new STREAM_START event. The stream start event can only
1598 * travel downstream synchronized with the buffer flow. It is expected
1599 * to be the first event that is sent for a new stream.
1601 * Source elements, demuxers and other elements that create new streams
1602 * are supposed to send this event as the first event of a new stream. It
1603 * should not be send after a flushing seek or in similar situations
1604 * and is used to mark the beginning of a new logical stream. Elements
1605 * combining multiple streams must ensure that this event is only forwarded
1606 * downstream once and not for every single input stream.
1608 * Returns: (transfer full): the new STREAM_START event.
1611 gst_event_new_stream_start (void)
1613 return gst_event_new_custom (GST_EVENT_STREAM_START, NULL);
1617 * gst_event_new_toc:
1618 * @toc: (transfer none): #GstToc structure.
1619 * @updated: whether @toc was updated or not.
1621 * Generate a TOC event from the given @toc. The purpose of the TOC event is to
1622 * inform elements that some kind of the TOC was found.
1624 * Returns: (transfer full): a new #GstEvent.
1627 gst_event_new_toc (GstToc * toc, gboolean updated)
1629 GstStructure *toc_struct;
1631 g_return_val_if_fail (toc != NULL, NULL);
1633 GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
1635 toc_struct = gst_structure_new_id (GST_QUARK (EVENT_TOC),
1636 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1637 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1639 return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
1643 * gst_event_parse_toc:
1644 * @event: a TOC event.
1645 * @toc: (out) (transfer full): pointer to #GstToc structure.
1646 * @updated: (out): pointer to store TOC updated flag.
1648 * Parse a TOC @event and store the results in the given @toc and @updated locations.
1651 gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
1653 const GstStructure *structure;
1655 g_return_if_fail (event != NULL);
1656 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
1657 g_return_if_fail (toc != NULL);
1659 structure = gst_event_get_structure (event);
1661 gst_structure_id_get (structure,
1662 GST_QUARK (TOC), GST_TYPE_TOC, toc,
1663 GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
1667 * gst_event_new_toc_select:
1668 * @uid: UID in the TOC to start playback from.
1670 * Generate a TOC select event with the given @uid. The purpose of the
1671 * TOC select event is to start playback based on the TOC's entry with the
1674 * Returns: a new #GstEvent.
1677 gst_event_new_toc_select (const gchar * uid)
1679 GstStructure *structure;
1681 g_return_val_if_fail (uid != NULL, NULL);
1683 GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
1685 structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
1686 GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
1688 return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
1692 * gst_event_parse_toc_select:
1693 * @event: a TOC select event.
1694 * @uid: (out): storage for the selection UID.
1696 * Parse a TOC select @event and store the results in the given @uid location.
1699 gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
1701 const GstStructure *structure;
1704 g_return_if_fail (event != NULL);
1705 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
1707 structure = gst_event_get_structure (event);
1708 val = gst_structure_id_get_value (structure, GST_QUARK (UID));
1711 *uid = g_strdup (g_value_get_string (val));
1716 * gst_event_new_segment_done:
1717 * @format: The format of the position being done
1718 * @position: The position of the segment being done
1720 * Create a new segment-done event. This event is sent by elements that
1721 * finish playback of a segment as a result of a segment seek.
1723 * Returns: (transfer full): a new #GstEvent
1726 gst_event_new_segment_done (GstFormat format, gint64 position)
1729 GstStructure *structure;
1731 GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
1733 structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
1734 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1735 GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
1737 event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
1743 * gst_event_parse_segment_done:
1744 * @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
1745 * @format: (out): Result location for the format, or NULL
1746 * @position: (out): Result location for the position, or NULL
1748 * Extracts the position and format from the segment done message.
1752 gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
1755 const GstStructure *structure;
1758 g_return_if_fail (event != NULL);
1759 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
1761 structure = gst_event_get_structure (event);
1763 val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
1765 *format = g_value_get_enum (val);
1767 val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
1768 if (position != NULL)
1769 *position = g_value_get_int64 (val);