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 specity 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"
88 static GType _gst_event_type = 0;
97 static GstEventQuarks event_quarks[] = {
98 {GST_EVENT_UNKNOWN, "unknown", 0},
99 {GST_EVENT_FLUSH_START, "flush-start", 0},
100 {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
101 {GST_EVENT_EOS, "eos", 0},
102 {GST_EVENT_NEWSEGMENT, "newsegment", 0},
103 {GST_EVENT_TAG, "tag", 0},
104 {GST_EVENT_BUFFERSIZE, "buffersize", 0},
105 {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
106 {GST_EVENT_QOS, "qos", 0},
107 {GST_EVENT_SEEK, "seek", 0},
108 {GST_EVENT_NAVIGATION, "navigation", 0},
109 {GST_EVENT_LATENCY, "latency", 0},
110 {GST_EVENT_STEP, "step", 0},
111 {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
112 {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
113 {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
114 {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
115 {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
121 _gst_event_initialize (void)
125 gst_event_get_type ();
126 g_type_class_ref (gst_seek_flags_get_type ());
127 g_type_class_ref (gst_seek_type_get_type ());
129 for (i = 0; event_quarks[i].name; i++) {
130 event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
135 * gst_event_type_get_name:
136 * @type: the event type
138 * Get a printable name for the given event type. Do not modify or free.
140 * Returns: a reference to the static name of the event.
143 gst_event_type_get_name (GstEventType type)
147 for (i = 0; event_quarks[i].name; i++) {
148 if (type == event_quarks[i].type)
149 return event_quarks[i].name;
155 * gst_event_type_to_quark:
156 * @type: the event type
158 * Get the unique quark for the given event type.
160 * Returns: the quark associated with the event type
163 gst_event_type_to_quark (GstEventType type)
167 for (i = 0; event_quarks[i].name; i++) {
168 if (type == event_quarks[i].type)
169 return event_quarks[i].quark;
175 * gst_event_type_get_flags:
176 * @type: a #GstEventType
178 * Gets the #GstEventTypeFlags associated with @type.
180 * Returns: a #GstEventTypeFlags.
183 gst_event_type_get_flags (GstEventType type)
185 GstEventTypeFlags ret;
187 ret = type & ((1 << GST_EVENT_TYPE_SHIFT) - 1);
193 gst_event_get_type (void)
195 if (G_UNLIKELY (_gst_event_type == 0)) {
196 _gst_event_type = gst_mini_object_register ("GstEvent");
198 return _gst_event_type;
202 _gst_event_free (GstEvent * event)
204 g_return_if_fail (event != NULL);
205 g_return_if_fail (GST_IS_EVENT (event));
207 GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
208 GST_EVENT_TYPE_NAME (event));
210 if (GST_EVENT_SRC (event)) {
211 gst_object_unref (GST_EVENT_SRC (event));
212 GST_EVENT_SRC (event) = NULL;
214 if (event->structure) {
215 gst_structure_set_parent_refcount (event->structure, NULL);
216 gst_structure_free (event->structure);
219 g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
222 static void gst_event_init (GstEvent * event, gsize size, GstEventType type);
225 _gst_event_copy (GstEvent * event)
229 copy = g_slice_new0 (GstEvent);
231 gst_event_init (copy, sizeof (GstEvent), GST_EVENT_TYPE (event));
233 GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
234 GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
236 if (GST_EVENT_SRC (event)) {
237 GST_EVENT_SRC (copy) = gst_object_ref (GST_EVENT_SRC (event));
239 if (event->structure) {
240 copy->structure = gst_structure_copy (event->structure);
241 gst_structure_set_parent_refcount (copy->structure,
242 ©->mini_object.refcount);
248 gst_event_init (GstEvent * event, gsize size, GstEventType type)
250 gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
252 event->mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
253 event->mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
255 GST_EVENT_TYPE (event) = type;
256 GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
257 GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
261 gst_event_new (GstEventType type)
265 event = g_slice_new0 (GstEvent);
267 GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
268 gst_event_type_get_name (type), type);
270 gst_event_init (event, sizeof (GstEvent), type);
276 * gst_event_new_custom:
277 * @type: The type of the new event
278 * @structure: (transfer full): the structure for the event. The event will
279 * take ownership of the structure.
281 * Create a new custom-typed event. This can be used for anything not
282 * handled by other event-specific functions to pass an event to another
285 * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
286 * assigning a free number and filling in the correct direction and
287 * serialization flags.
289 * New custom events can also be created by subclassing the event type if
292 * Returns: (transfer full): the new custom event.
295 gst_event_new_custom (GstEventType type, GstStructure * structure)
299 /* structure must not have a parent */
301 g_return_val_if_fail (structure->parent_refcount == NULL, NULL);
303 event = gst_event_new (type);
305 gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
306 event->structure = structure;
312 * gst_event_get_structure:
313 * @event: The #GstEvent.
315 * Access the structure of the event.
317 * Returns: The structure of the event. The structure is still
318 * owned by the event, which means that you should not free it and
319 * that the pointer becomes invalid when you free the event.
324 gst_event_get_structure (GstEvent * event)
326 g_return_val_if_fail (GST_IS_EVENT (event), NULL);
328 return event->structure;
332 * gst_event_has_name:
333 * @event: The #GstEvent.
334 * @name: name to check
336 * Checks if @event has the given @name. This function is usually used to
337 * check the name of a custom event.
339 * Returns: %TRUE if @name matches the name of the event structure.
344 gst_event_has_name (GstEvent * event, const gchar * name)
346 g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
348 if (event->structure == NULL)
351 return gst_structure_has_name (event->structure, name);
355 * gst_event_get_seqnum:
356 * @event: A #GstEvent.
358 * Retrieve the sequence number of a event.
360 * Events have ever-incrementing sequence numbers, which may also be set
361 * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
362 * indicate that a event corresponds to some other set of events or messages,
363 * for example an EOS event corresponding to a SEEK event. It is considered good
364 * practice to make this correspondence when possible, though it is not
367 * Note that events and messages share the same sequence number incrementor;
368 * two events or messages will never not have the same sequence number unless
369 * that correspondence was made explicitly.
371 * Returns: The event's sequence number.
378 gst_event_get_seqnum (GstEvent * event)
380 g_return_val_if_fail (GST_IS_EVENT (event), -1);
382 return GST_EVENT_SEQNUM (event);
386 * gst_event_set_seqnum:
387 * @event: A #GstEvent.
388 * @seqnum: A sequence number.
390 * Set the sequence number of a event.
392 * This function might be called by the creator of a event to indicate that the
393 * event relates to other events or messages. See gst_event_get_seqnum() for
401 gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
403 g_return_if_fail (GST_IS_EVENT (event));
405 GST_EVENT_SEQNUM (event) = seqnum;
408 /* FIXME 0.11: It would be nice to have flush events
409 * that don't reset the running time in the sinks
413 * gst_event_new_flush_start:
415 * Allocate a new flush start event. The flush start event can be sent
416 * upstream and downstream and travels out-of-bounds with the dataflow.
418 * It marks pads as being flushing and will make them return
419 * #GST_FLOW_WRONG_STATE when used for data flow with gst_pad_push(),
420 * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and
421 * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received
422 * on a flushing pad will return %FALSE immediately.
424 * Elements should unlock any blocking functions and exit their streaming
425 * functions as fast as possible when this event is received.
427 * This event is typically generated after a seek to flush out all queued data
428 * in the pipeline so that the new media is played as soon as possible.
430 * Returns: (transfer full): a new flush start event.
433 gst_event_new_flush_start (void)
435 return gst_event_new (GST_EVENT_FLUSH_START);
439 * gst_event_new_flush_stop:
441 * Allocate a new flush stop event. The flush stop event can be sent
442 * upstream and downstream and travels serialized with the dataflow.
443 * It is typically sent after sending a FLUSH_START event to make the
444 * pads accept data again.
446 * Elements can process this event synchronized with the dataflow since
447 * the preceeding FLUSH_START event stopped the dataflow.
449 * This event is typically generated to complete a seek and to resume
452 * Returns: (transfer full): a new flush stop event.
455 gst_event_new_flush_stop (void)
457 return gst_event_new (GST_EVENT_FLUSH_STOP);
463 * Create a new EOS event. The eos event can only travel downstream
464 * synchronized with the buffer flow. Elements that receive the EOS
465 * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn
466 * when data after the EOS event arrives.
468 * The EOS event will travel down to the sink elements in the pipeline
469 * which will then post the #GST_MESSAGE_EOS on the bus after they have
470 * finished playing any buffered data.
472 * When all sinks have posted an EOS message, an EOS message is
473 * forwarded to the application.
475 * The EOS event itself will not cause any state transitions of the pipeline.
477 * Returns: (transfer full): the new EOS event.
480 gst_event_new_eos (void)
482 return gst_event_new (GST_EVENT_EOS);
486 * gst_event_new_new_segment:
487 * @update: is this segment an update to a previous one
488 * @rate: a new rate for playback
489 * @format: The format of the segment values
490 * @start: the start value of the segment
491 * @stop: the stop value of the segment
492 * @time: the time value of the segment
494 * Allocate a new newsegment event with the given format/values tripplets
496 * This method calls gst_event_new_new_segment_full() passing a default
497 * value of 1.0 for applied_rate
499 * Returns: (transfer full): a new newsegment event.
502 gst_event_new_new_segment (gboolean update, gdouble rate, GstFormat format,
503 gint64 start, gint64 stop, gint64 time)
505 return gst_event_new_new_segment_full (update, rate, 1.0, format, start,
510 * gst_event_parse_new_segment:
511 * @event: The event to query
512 * @update: (out): A pointer to the update flag of the segment
513 * @rate: (out): A pointer to the rate of the segment
514 * @format: (out): A pointer to the format of the newsegment values
515 * @start: (out): A pointer to store the start value in
516 * @stop: (out): A pointer to store the stop value in
517 * @time: (out): A pointer to store the time value in
519 * Get the update flag, rate, format, start, stop and time in the
520 * newsegment event. In general, gst_event_parse_new_segment_full() should
521 * be used instead of this, to also retrieve the applied_rate value of the
522 * segment. See gst_event_new_new_segment_full() for a full description
523 * of the newsegment event.
526 gst_event_parse_new_segment (GstEvent * event, gboolean * update,
527 gdouble * rate, GstFormat * format, gint64 * start,
528 gint64 * stop, gint64 * time)
530 gst_event_parse_new_segment_full (event, update, rate, NULL, format, start,
535 * gst_event_new_new_segment_full:
536 * @update: Whether this segment is an update to a previous one
537 * @rate: A new rate for playback
538 * @applied_rate: The rate factor which has already been applied
539 * @format: The format of the segment values
540 * @start: The start value of the segment
541 * @stop: The stop value of the segment
542 * @time: the time value of the segment
544 * Allocate a new newsegment event with the given format/values triplets.
546 * The newsegment event marks the range of buffers to be processed. All
547 * data not within the segment range is not to be processed. This can be
548 * used intelligently by plugins to apply more efficient methods of skipping
549 * unneeded data. The valid range is expressed with the @start and @stop
552 * The time value of the segment is used in conjunction with the start
553 * value to convert the buffer timestamps into the stream time. This is
554 * usually done in sinks to report the current stream_time.
555 * @time represents the stream_time of a buffer carrying a timestamp of
556 * @start. @time cannot be -1.
558 * @start cannot be -1, @stop can be -1. If there
559 * is a valid @stop given, it must be greater or equal the @start, including
560 * when the indicated playback @rate is < 0.
562 * The @applied_rate value provides information about any rate adjustment that
563 * has already been made to the timestamps and content on the buffers of the
564 * stream. (@rate * @applied_rate) should always equal the rate that has been
565 * requested for playback. For example, if an element has an input segment
566 * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
567 * incoming timestamps and buffer content by half and output a newsegment event
568 * with @rate of 1.0 and @applied_rate of 2.0
570 * After a newsegment event, the buffer stream time is calculated with:
572 * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
574 * Returns: (transfer full): a new newsegment event.
579 gst_event_new_new_segment_full (gboolean update, gdouble rate,
580 gdouble applied_rate, GstFormat format, gint64 start, gint64 stop,
584 GstStructure *structure;
586 g_return_val_if_fail (rate != 0.0, NULL);
587 g_return_val_if_fail (applied_rate != 0.0, NULL);
589 if (format == GST_FORMAT_TIME) {
590 GST_CAT_INFO (GST_CAT_EVENT,
591 "creating newsegment update %d, rate %lf, format GST_FORMAT_TIME, "
592 "start %" GST_TIME_FORMAT ", stop %" GST_TIME_FORMAT
593 ", time %" GST_TIME_FORMAT,
594 update, rate, GST_TIME_ARGS (start),
595 GST_TIME_ARGS (stop), GST_TIME_ARGS (time));
597 GST_CAT_INFO (GST_CAT_EVENT,
598 "creating newsegment update %d, rate %lf, format %s, "
599 "start %" G_GINT64_FORMAT ", stop %" G_GINT64_FORMAT ", time %"
600 G_GINT64_FORMAT, update, rate, gst_format_get_name (format), start,
604 g_return_val_if_fail (time != -1, NULL);
605 g_return_val_if_fail (start != -1, NULL);
607 g_return_val_if_fail (start <= stop, NULL);
609 structure = gst_structure_id_new (GST_QUARK (EVENT_NEWSEGMENT),
610 GST_QUARK (UPDATE), G_TYPE_BOOLEAN, update,
611 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
612 GST_QUARK (APPLIED_RATE), G_TYPE_DOUBLE, applied_rate,
613 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
614 GST_QUARK (START), G_TYPE_INT64, start,
615 GST_QUARK (STOP), G_TYPE_INT64, stop,
616 GST_QUARK (TIME), G_TYPE_INT64, time, NULL);
617 event = gst_event_new_custom (GST_EVENT_NEWSEGMENT, structure);
623 * gst_event_parse_new_segment_full:
624 * @event: The event to query
625 * @update: (out): A pointer to the update flag of the segment
626 * @rate: (out): A pointer to the rate of the segment
627 * @applied_rate: (out): A pointer to the applied_rate of the segment
628 * @format: (out): A pointer to the format of the newsegment values
629 * @start: (out): A pointer to store the start value in
630 * @stop: (out): A pointer to store the stop value in
631 * @time: (out): A pointer to store the time value in
633 * Get the update, rate, applied_rate, format, start, stop and
634 * time in the newsegment event. See gst_event_new_new_segment_full()
635 * for a full description of the newsegment event.
640 gst_event_parse_new_segment_full (GstEvent * event, gboolean * update,
641 gdouble * rate, gdouble * applied_rate, GstFormat * format,
642 gint64 * start, gint64 * stop, gint64 * time)
644 const GstStructure *structure;
646 g_return_if_fail (GST_IS_EVENT (event));
647 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_NEWSEGMENT);
649 structure = event->structure;
650 if (G_LIKELY (update))
652 g_value_get_boolean (gst_structure_id_get_value (structure,
653 GST_QUARK (UPDATE)));
656 g_value_get_double (gst_structure_id_get_value (structure,
658 if (G_LIKELY (applied_rate))
660 g_value_get_double (gst_structure_id_get_value (structure,
661 GST_QUARK (APPLIED_RATE)));
662 if (G_LIKELY (format))
664 g_value_get_enum (gst_structure_id_get_value (structure,
665 GST_QUARK (FORMAT)));
666 if (G_LIKELY (start))
668 g_value_get_int64 (gst_structure_id_get_value (structure,
672 g_value_get_int64 (gst_structure_id_get_value (structure,
676 g_value_get_int64 (gst_structure_id_get_value (structure,
682 * @taglist: (transfer full): metadata list. The event will take ownership
685 * Generates a metadata tag event from the given @taglist.
687 * Returns: (transfer full): a new #GstEvent
690 gst_event_new_tag (GstTagList * taglist)
692 g_return_val_if_fail (taglist != NULL, NULL);
694 return gst_event_new_custom (GST_EVENT_TAG, (GstStructure *) taglist);
698 * gst_event_parse_tag:
699 * @event: a tag event
700 * @taglist: (out) (transfer none): pointer to metadata list
702 * Parses a tag @event and stores the results in the given @taglist location.
703 * No reference to the taglist will be returned, it remains valid only until
704 * the @event is freed. Don't modify or free the taglist, make a copy if you
705 * want to modify it or store it for later use.
708 gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
710 g_return_if_fail (GST_IS_EVENT (event));
711 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
714 *taglist = (GstTagList *) event->structure;
717 /* buffersize event */
719 * gst_event_new_buffer_size:
720 * @format: buffer format
721 * @minsize: minimum buffer size
722 * @maxsize: maximum buffer size
723 * @async: thread behavior
725 * Create a new buffersize event. The event is sent downstream and notifies
726 * elements that they should provide a buffer of the specified dimensions.
728 * When the @async flag is set, a thread boundary is prefered.
730 * Returns: (transfer full): a new #GstEvent
733 gst_event_new_buffer_size (GstFormat format, gint64 minsize,
734 gint64 maxsize, gboolean async)
737 GstStructure *structure;
739 GST_CAT_INFO (GST_CAT_EVENT,
740 "creating buffersize format %s, minsize %" G_GINT64_FORMAT
741 ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
742 minsize, maxsize, async);
744 structure = gst_structure_id_new (GST_QUARK (EVENT_BUFFER_SIZE),
745 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
746 GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
747 GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
748 GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
749 event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
755 * gst_event_parse_buffer_size:
756 * @event: The event to query
757 * @format: (out): A pointer to store the format in
758 * @minsize: (out): A pointer to store the minsize in
759 * @maxsize: (out): A pointer to store the maxsize in
760 * @async: (out): A pointer to store the async-flag in
762 * Get the format, minsize, maxsize and async-flag in the buffersize event.
765 gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
766 gint64 * minsize, gint64 * maxsize, gboolean * async)
768 const GstStructure *structure;
770 g_return_if_fail (GST_IS_EVENT (event));
771 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
773 structure = event->structure;
776 g_value_get_enum (gst_structure_id_get_value (structure,
777 GST_QUARK (FORMAT)));
780 g_value_get_int64 (gst_structure_id_get_value (structure,
781 GST_QUARK (MINSIZE)));
784 g_value_get_int64 (gst_structure_id_get_value (structure,
785 GST_QUARK (MAXSIZE)));
788 g_value_get_boolean (gst_structure_id_get_value (structure,
794 * @proportion: the proportion of the qos message
795 * @diff: The time difference of the last Clock sync
796 * @timestamp: The timestamp of the buffer
798 * Allocate a new qos event with the given values. This function calls
799 * gst_event_new_qos_full() with the type set to #GST_QOS_TYPE_OVERFLOW
800 * when diff is negative (buffers are in time) and #GST_QOS_TYPE_UNDERFLOW
801 * when @diff is positive (buffers are late).
803 * Returns: (transfer full): a new QOS event.
806 gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
807 GstClockTime timestamp)
812 type = GST_QOS_TYPE_OVERFLOW;
814 type = GST_QOS_TYPE_UNDERFLOW;
816 return gst_event_new_qos_full (type, proportion, diff, timestamp);
820 * gst_event_new_qos_full:
821 * @type: the QoS type
822 * @proportion: the proportion of the qos message
823 * @diff: The time difference of the last Clock sync
824 * @timestamp: The timestamp of the buffer
826 * Allocate a new qos event with the given values.
827 * The QOS event is generated in an element that wants an upstream
828 * element to either reduce or increase its rate because of
829 * high/low CPU load or other resource usage such as network performance or
830 * throttling. Typically sinks generate these events for each buffer
833 * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
834 * used when a buffer arrived in time or when the sink cannot keep up with
835 * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
836 * receiving buffers fast enough and thus has to drop late buffers.
837 * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
838 * by the application, for example to reduce power consumption.
840 * @proportion indicates the real-time performance of the streaming in the
841 * element that generated the QoS event (usually the sink). The value is
842 * generally computed based on more long term statistics about the streams
843 * timestamps compared to the clock.
844 * A value < 1.0 indicates that the upstream element is producing data faster
845 * than real-time. A value > 1.0 indicates that the upstream element is not
846 * producing data fast enough. 1.0 is the ideal @proportion value. The
847 * proportion value can safely be used to lower or increase the quality of
850 * @diff is the difference against the clock in running time of the last
851 * buffer that caused the element to generate the QOS event. A negative value
852 * means that the buffer with @timestamp arrived in time. A positive value
853 * indicates how late the buffer with @timestamp was. When throttling is
854 * enabled, @diff will be set to the requested throttling interval.
856 * @timestamp is the timestamp of the last buffer that cause the element
857 * to generate the QOS event. It is expressed in running time and thus an ever
860 * The upstream element can use the @diff and @timestamp values to decide
861 * whether to process more buffers. For possitive @diff, all buffers with
862 * timestamp <= @timestamp + @diff will certainly arrive late in the sink
863 * as well. A (negative) @diff value so that @timestamp + @diff would yield a
864 * result smaller than 0 is not allowed.
866 * The application can use general event probes to intercept the QoS
867 * event and implement custom application specific QoS handling.
869 * Returns: (transfer full): a new QOS event.
874 gst_event_new_qos_full (GstQOSType type, gdouble proportion,
875 GstClockTimeDiff diff, GstClockTime timestamp)
878 GstStructure *structure;
880 /* diff must be positive or timestamp + diff must be positive */
881 g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
883 GST_CAT_INFO (GST_CAT_EVENT,
884 "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
885 ", timestamp %" GST_TIME_FORMAT, type, proportion,
886 diff, GST_TIME_ARGS (timestamp));
888 structure = gst_structure_id_new (GST_QUARK (EVENT_QOS),
889 GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
890 GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
891 GST_QUARK (DIFF), G_TYPE_INT64, diff,
892 GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
893 event = gst_event_new_custom (GST_EVENT_QOS, structure);
899 * gst_event_parse_qos:
900 * @event: The event to query
901 * @proportion: (out): A pointer to store the proportion in
902 * @diff: (out): A pointer to store the diff in
903 * @timestamp: (out): A pointer to store the timestamp in
905 * Get the proportion, diff and timestamp in the qos event. See
906 * gst_event_new_qos() for more information about the different QoS values.
909 gst_event_parse_qos (GstEvent * event, gdouble * proportion,
910 GstClockTimeDiff * diff, GstClockTime * timestamp)
912 gst_event_parse_qos_full (event, NULL, proportion, diff, timestamp);
916 * gst_event_parse_qos_full:
917 * @event: The event to query
918 * @type: (out): A pointer to store the QoS type in
919 * @proportion: (out): A pointer to store the proportion in
920 * @diff: (out): A pointer to store the diff in
921 * @timestamp: (out): A pointer to store the timestamp in
923 * Get the type, proportion, diff and timestamp in the qos event. See
924 * gst_event_new_qos_full() for more information about the different QoS values.
929 gst_event_parse_qos_full (GstEvent * event, GstQOSType * type,
930 gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
932 const GstStructure *structure;
934 g_return_if_fail (GST_IS_EVENT (event));
935 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
937 structure = event->structure;
940 g_value_get_enum (gst_structure_id_get_value (structure,
944 g_value_get_double (gst_structure_id_get_value (structure,
945 GST_QUARK (PROPORTION)));
948 g_value_get_int64 (gst_structure_id_get_value (structure,
952 g_value_get_uint64 (gst_structure_id_get_value (structure,
953 GST_QUARK (TIMESTAMP)));
957 * gst_event_new_seek:
958 * @rate: The new playback rate
959 * @format: The format of the seek values
960 * @flags: The optional seek flags
961 * @start_type: The type and flags for the new start position
962 * @start: The value of the new start position
963 * @stop_type: The type and flags for the new stop position
964 * @stop: The value of the new stop position
966 * Allocate a new seek event with the given parameters.
968 * The seek event configures playback of the pipeline between @start to @stop
969 * at the speed given in @rate, also called a playback segment.
970 * The @start and @stop values are expressed in @format.
972 * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
973 * Negatives values means backwards playback. A value of 0.0 for the
974 * rate is not allowed and should be accomplished instead by PAUSING the
977 * A pipeline has a default playback segment configured with a start
978 * position of 0, a stop position of -1 and a rate of 1.0. The currently
979 * configured playback segment can be queried with #GST_QUERY_SEGMENT.
981 * @start_type and @stop_type specify how to adjust the currently configured
982 * start and stop fields in playback segment. Adjustments can be made relative
983 * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
984 * means that the position should not be updated.
986 * When the rate is positive and @start has been updated, playback will start
987 * from the newly configured start position.
989 * For negative rates, playback will start from the newly configured stop
990 * position (if any). If the stop position if updated, it must be different from
991 * -1 for negative rates.
993 * It is not possible to seek relative to the current playback position, to do
994 * this, PAUSE the pipeline, query the current playback position with
995 * #GST_QUERY_POSITION and update the playback segment current position with a
996 * #GST_SEEK_TYPE_SET to the desired position.
998 * Returns: (transfer full): a new seek event.
1001 gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
1002 GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
1005 GstStructure *structure;
1007 g_return_val_if_fail (rate != 0.0, NULL);
1009 if (format == GST_FORMAT_TIME) {
1010 GST_CAT_INFO (GST_CAT_EVENT,
1011 "creating seek rate %lf, format TIME, flags %d, "
1012 "start_type %d, start %" GST_TIME_FORMAT ", "
1013 "stop_type %d, stop %" GST_TIME_FORMAT,
1014 rate, flags, start_type, GST_TIME_ARGS (start),
1015 stop_type, GST_TIME_ARGS (stop));
1017 GST_CAT_INFO (GST_CAT_EVENT,
1018 "creating seek rate %lf, format %s, flags %d, "
1019 "start_type %d, start %" G_GINT64_FORMAT ", "
1020 "stop_type %d, stop %" G_GINT64_FORMAT,
1021 rate, gst_format_get_name (format), flags, start_type, start, stop_type,
1025 structure = gst_structure_id_new (GST_QUARK (EVENT_SEEK),
1026 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1027 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1028 GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
1029 GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
1030 GST_QUARK (CUR), G_TYPE_INT64, start,
1031 GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
1032 GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
1033 event = gst_event_new_custom (GST_EVENT_SEEK, structure);
1039 * gst_event_parse_seek:
1040 * @event: a seek event
1041 * @rate: (out): result location for the rate
1042 * @format: (out): result location for the stream format
1043 * @flags: (out): result location for the #GstSeekFlags
1044 * @start_type: (out): result location for the #GstSeekType of the start position
1045 * @start: (out): result location for the start postion expressed in @format
1046 * @stop_type: (out): result location for the #GstSeekType of the stop position
1047 * @stop: (out): result location for the stop postion expressed in @format
1049 * Parses a seek @event and stores the results in the given result locations.
1052 gst_event_parse_seek (GstEvent * event, gdouble * rate,
1053 GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
1054 gint64 * start, GstSeekType * stop_type, gint64 * stop)
1056 const GstStructure *structure;
1058 g_return_if_fail (GST_IS_EVENT (event));
1059 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
1061 structure = event->structure;
1064 g_value_get_double (gst_structure_id_get_value (structure,
1068 g_value_get_enum (gst_structure_id_get_value (structure,
1069 GST_QUARK (FORMAT)));
1072 g_value_get_flags (gst_structure_id_get_value (structure,
1073 GST_QUARK (FLAGS)));
1076 g_value_get_enum (gst_structure_id_get_value (structure,
1077 GST_QUARK (CUR_TYPE)));
1080 g_value_get_int64 (gst_structure_id_get_value (structure,
1084 g_value_get_enum (gst_structure_id_get_value (structure,
1085 GST_QUARK (STOP_TYPE)));
1088 g_value_get_int64 (gst_structure_id_get_value (structure,
1093 * gst_event_new_navigation:
1094 * @structure: (transfer full): description of the event. The event will take
1095 * ownership of the structure.
1097 * Create a new navigation event from the given description.
1099 * Returns: (transfer full): a new #GstEvent
1102 gst_event_new_navigation (GstStructure * structure)
1104 g_return_val_if_fail (structure != NULL, NULL);
1106 return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
1110 * gst_event_new_latency:
1111 * @latency: the new latency value
1113 * Create a new latency event. The event is sent upstream from the sinks and
1114 * notifies elements that they should add an additional @latency to the
1115 * running time before synchronising against the clock.
1117 * The latency is mostly used in live sinks and is always expressed in
1120 * Returns: (transfer full): a new #GstEvent
1125 gst_event_new_latency (GstClockTime latency)
1128 GstStructure *structure;
1130 GST_CAT_INFO (GST_CAT_EVENT,
1131 "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
1133 structure = gst_structure_id_new (GST_QUARK (EVENT_LATENCY),
1134 GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
1135 event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
1141 * gst_event_parse_latency:
1142 * @event: The event to query
1143 * @latency: (out): A pointer to store the latency in.
1145 * Get the latency in the latency event.
1150 gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
1152 g_return_if_fail (GST_IS_EVENT (event));
1153 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
1157 g_value_get_uint64 (gst_structure_id_get_value (event->structure,
1158 GST_QUARK (LATENCY)));
1162 * gst_event_new_step:
1163 * @format: the format of @amount
1164 * @amount: the amount of data to step
1165 * @rate: the step rate
1166 * @flush: flushing steps
1167 * @intermediate: intermediate steps
1169 * Create a new step event. The purpose of the step event is to instruct a sink
1170 * to skip @amount (expressed in @format) of media. It can be used to implement
1171 * stepping through the video frame by frame or for doing fast trick modes.
1173 * A rate of <= 0.0 is not allowed, pause the pipeline or reverse the playback
1174 * direction of the pipeline to get the same effect.
1176 * The @flush flag will clear any pending data in the pipeline before starting
1177 * the step operation.
1179 * The @intermediate flag instructs the pipeline that this step operation is
1180 * part of a larger step operation.
1182 * Returns: (transfer full): a new #GstEvent
1187 gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
1188 gboolean flush, gboolean intermediate)
1191 GstStructure *structure;
1193 g_return_val_if_fail (rate > 0.0, NULL);
1195 GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
1197 structure = gst_structure_id_new (GST_QUARK (EVENT_STEP),
1198 GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
1199 GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
1200 GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
1201 GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
1202 GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
1203 event = gst_event_new_custom (GST_EVENT_STEP, structure);
1209 * gst_event_parse_step:
1210 * @event: The event to query
1211 * @format: (out) (allow-none): a pointer to store the format in
1212 * @amount: (out) (allow-none): a pointer to store the amount in
1213 * @rate: (out) (allow-none): a pointer to store the rate in
1214 * @flush: (out) (allow-none): a pointer to store the flush boolean in
1215 * @intermediate: (out) (allow-none): a pointer to store the intermediate
1218 * Parse the step event.
1223 gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
1224 gdouble * rate, gboolean * flush, gboolean * intermediate)
1226 const GstStructure *structure;
1228 g_return_if_fail (GST_IS_EVENT (event));
1229 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
1231 structure = event->structure;
1233 *format = g_value_get_enum (gst_structure_id_get_value (structure,
1234 GST_QUARK (FORMAT)));
1236 *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
1237 GST_QUARK (AMOUNT)));
1239 *rate = g_value_get_double (gst_structure_id_get_value (structure,
1242 *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
1243 GST_QUARK (FLUSH)));
1245 *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
1246 GST_QUARK (INTERMEDIATE)));
1250 * gst_event_new_sink_message:
1251 * @msg: (transfer none): the #GstMessage to be posted
1253 * Create a new sink-message event. The purpose of the sink-message event is
1254 * to instruct a sink to post the message contained in the event synchronized
1257 * Returns: (transfer full): a new #GstEvent
1261 /* FIXME 0.11: take ownership of msg for consistency? */
1263 gst_event_new_sink_message (GstMessage * msg)
1266 GstStructure *structure;
1268 g_return_val_if_fail (msg != NULL, NULL);
1270 GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
1272 structure = gst_structure_id_new (GST_QUARK (EVENT_SINK_MESSAGE),
1273 GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
1274 event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
1280 * gst_event_parse_sink_message:
1281 * @event: The event to query
1282 * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
1284 * Parse the sink-message event. Unref @msg after usage.
1289 gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
1291 const GstStructure *structure;
1293 g_return_if_fail (GST_IS_EVENT (event));
1294 g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
1296 structure = event->structure;
1299 GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
1300 (structure, GST_QUARK (MESSAGE))));