Imported Upstream version 0.11.1
diff --git a/gst/gstevent.c b/gst/gstevent.c
new file mode 100644
index 0000000..030b9d4
--- /dev/null
+++ b/gst/gstevent.c
@@ -0,0 +1,1311 @@
+/* GStreamer
+ * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
+ * 2000 Wim Taymans <wim.taymans@chello.be>
+ * 2005 Wim Taymans <wim@fluendo.com>
+ *
+ * gstevent.c: GstEvent subsystem
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+/**
+ * SECTION:gstevent
+ * @short_description: Structure describing events that are passed up and down
+ * a pipeline
+ * @see_also: #GstPad, #GstElement
+ *
+ * The event class provides factory methods to construct events for sending
+ * and functions to query (parse) received events.
+ *
+ * Events are usually created with gst_event_new_*() which takes event-type
+ * specific parameters as arguments.
+ * To send an event application will usually use gst_element_send_event() and
+ * elements will use gst_pad_send_event() or gst_pad_push_event().
+ * The event should be unreffed with gst_event_unref() if it has not been sent.
+ *
+ * Events that have been received can be parsed with their respective
+ * gst_event_parse_*() functions. It is valid to pass %NULL for unwanted details.
+ *
+ * Events are passed between elements in parallel to the data stream. Some events
+ * are serialized with buffers, others are not. Some events only travel downstream,
+ * others only upstream. Some events can travel both upstream and downstream.
+ *
+ * The events are used to signal special conditions in the datastream such as
+ * EOS (end of stream) or the start of a new stream-segment.
+ * Events are also used to flush the pipeline of any pending data.
+ *
+ * Most of the event API is used inside plugins. Applications usually only
+ * construct and use seek events.
+ * To do that gst_event_new_seek() is used to create a seek event. It takes
+ * the needed parameters to specify seeking time and mode.
+ * <example>
+ * <title>performing a seek on a pipeline</title>
+ * <programlisting>
+ * GstEvent *event;
+ * gboolean result;
+ * ...
+ * // construct a seek event to play the media from second 2 to 5, flush
+ * // the pipeline to decrease latency.
+ * event = gst_event_new_seek (1.0,
+ * GST_FORMAT_TIME,
+ * GST_SEEK_FLAG_FLUSH,
+ * GST_SEEK_TYPE_SET, 2 * GST_SECOND,
+ * GST_SEEK_TYPE_SET, 5 * GST_SECOND);
+ * ...
+ * result = gst_element_send_event (pipeline, event);
+ * if (!result)
+ * g_warning ("seek failed");
+ * ...
+ * </programlisting>
+ * </example>
+ *
+ * Last reviewed on 2006-09-6 (0.10.10)
+ */
+
+
+#include "gst_private.h"
+#include <string.h> /* memcpy */
+
+#include "gstinfo.h"
+#include "gstevent.h"
+#include "gstenumtypes.h"
+#include "gstutils.h"
+#include "gstquark.h"
+
+GType _gst_event_type = 0;
+
+typedef struct
+{
+ GstEvent event;
+
+ GstStructure *structure;
+} GstEventImpl;
+
+#define GST_EVENT_STRUCTURE(e) (((GstEventImpl *)(e))->structure)
+
+typedef struct
+{
+ const gint type;
+ const gchar *name;
+ GQuark quark;
+} GstEventQuarks;
+
+static GstEventQuarks event_quarks[] = {
+ {GST_EVENT_UNKNOWN, "unknown", 0},
+ {GST_EVENT_FLUSH_START, "flush-start", 0},
+ {GST_EVENT_FLUSH_STOP, "flush-stop", 0},
+ {GST_EVENT_EOS, "eos", 0},
+ {GST_EVENT_CAPS, "caps", 0},
+ {GST_EVENT_SEGMENT, "segment", 0},
+ {GST_EVENT_TAG, "tag", 0},
+ {GST_EVENT_BUFFERSIZE, "buffersize", 0},
+ {GST_EVENT_SINK_MESSAGE, "sink-message", 0},
+ {GST_EVENT_QOS, "qos", 0},
+ {GST_EVENT_SEEK, "seek", 0},
+ {GST_EVENT_NAVIGATION, "navigation", 0},
+ {GST_EVENT_LATENCY, "latency", 0},
+ {GST_EVENT_STEP, "step", 0},
+ {GST_EVENT_RECONFIGURE, "reconfigure", 0},
+ {GST_EVENT_CUSTOM_UPSTREAM, "custom-upstream", 0},
+ {GST_EVENT_CUSTOM_DOWNSTREAM, "custom-downstream", 0},
+ {GST_EVENT_CUSTOM_DOWNSTREAM_OOB, "custom-downstream-oob", 0},
+ {GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
+ {GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
+
+ {0, NULL, 0}
+};
+
+GST_DEFINE_MINI_OBJECT_TYPE (GstEvent, gst_event);
+
+void
+_priv_gst_event_initialize (void)
+{
+ gint i;
+
+ _gst_event_type = gst_event_get_type ();
+
+ g_type_class_ref (gst_seek_flags_get_type ());
+ g_type_class_ref (gst_seek_type_get_type ());
+
+ for (i = 0; event_quarks[i].name; i++) {
+ event_quarks[i].quark = g_quark_from_static_string (event_quarks[i].name);
+ }
+}
+
+/**
+ * gst_event_type_get_name:
+ * @type: the event type
+ *
+ * Get a printable name for the given event type. Do not modify or free.
+ *
+ * Returns: a reference to the static name of the event.
+ */
+const gchar *
+gst_event_type_get_name (GstEventType type)
+{
+ gint i;
+
+ for (i = 0; event_quarks[i].name; i++) {
+ if (type == event_quarks[i].type)
+ return event_quarks[i].name;
+ }
+ return "unknown";
+}
+
+/**
+ * gst_event_type_to_quark:
+ * @type: the event type
+ *
+ * Get the unique quark for the given event type.
+ *
+ * Returns: the quark associated with the event type
+ */
+GQuark
+gst_event_type_to_quark (GstEventType type)
+{
+ gint i;
+
+ for (i = 0; event_quarks[i].name; i++) {
+ if (type == event_quarks[i].type)
+ return event_quarks[i].quark;
+ }
+ return 0;
+}
+
+/**
+ * gst_event_type_get_flags:
+ * @type: a #GstEventType
+ *
+ * Gets the #GstEventTypeFlags associated with @type.
+ *
+ * Returns: a #GstEventTypeFlags.
+ */
+GstEventTypeFlags
+gst_event_type_get_flags (GstEventType type)
+{
+ GstEventTypeFlags ret;
+
+ ret = type & ((1 << GST_EVENT_STICKY_SHIFT) - 1);
+
+ return ret;
+}
+
+static void
+_gst_event_free (GstEvent * event)
+{
+ GstStructure *s;
+
+ g_return_if_fail (event != NULL);
+ g_return_if_fail (GST_IS_EVENT (event));
+
+ GST_CAT_LOG (GST_CAT_EVENT, "freeing event %p type %s", event,
+ GST_EVENT_TYPE_NAME (event));
+
+ s = GST_EVENT_STRUCTURE (event);
+
+ if (s) {
+ gst_structure_set_parent_refcount (s, NULL);
+ gst_structure_free (s);
+ }
+
+ g_slice_free1 (GST_MINI_OBJECT_SIZE (event), event);
+}
+
+static void gst_event_init (GstEventImpl * event, gsize size,
+ GstEventType type);
+
+static GstEvent *
+_gst_event_copy (GstEvent * event)
+{
+ GstEventImpl *copy;
+ GstStructure *s;
+
+ copy = g_slice_new0 (GstEventImpl);
+
+ gst_event_init (copy, sizeof (GstEventImpl), GST_EVENT_TYPE (event));
+
+ GST_EVENT_TIMESTAMP (copy) = GST_EVENT_TIMESTAMP (event);
+ GST_EVENT_SEQNUM (copy) = GST_EVENT_SEQNUM (event);
+
+ s = GST_EVENT_STRUCTURE (event);
+ if (s) {
+ GST_EVENT_STRUCTURE (copy) = gst_structure_copy (s);
+ gst_structure_set_parent_refcount (GST_EVENT_STRUCTURE (copy),
+ ©->event.mini_object.refcount);
+ }
+ return GST_EVENT_CAST (copy);
+}
+
+static void
+gst_event_init (GstEventImpl * event, gsize size, GstEventType type)
+{
+ gst_mini_object_init (GST_MINI_OBJECT_CAST (event), _gst_event_type, size);
+
+ event->event.mini_object.copy = (GstMiniObjectCopyFunction) _gst_event_copy;
+ event->event.mini_object.free = (GstMiniObjectFreeFunction) _gst_event_free;
+
+ GST_EVENT_TYPE (event) = type;
+ GST_EVENT_TIMESTAMP (event) = GST_CLOCK_TIME_NONE;
+ GST_EVENT_SEQNUM (event) = gst_util_seqnum_next ();
+}
+
+static GstEvent *
+gst_event_new (GstEventType type)
+{
+ GstEventImpl *event;
+
+ event = g_slice_new0 (GstEventImpl);
+
+ GST_CAT_DEBUG (GST_CAT_EVENT, "creating new event %p %s %d", event,
+ gst_event_type_get_name (type), type);
+
+ gst_event_init (event, sizeof (GstEventImpl), type);
+
+ return GST_EVENT_CAST (event);
+}
+
+/**
+ * gst_event_new_custom:
+ * @type: The type of the new event
+ * @structure: (transfer full): the structure for the event. The event will
+ * take ownership of the structure.
+ *
+ * Create a new custom-typed event. This can be used for anything not
+ * handled by other event-specific functions to pass an event to another
+ * element.
+ *
+ * Make sure to allocate an event type with the #GST_EVENT_MAKE_TYPE macro,
+ * assigning a free number and filling in the correct direction and
+ * serialization flags.
+ *
+ * New custom events can also be created by subclassing the event type if
+ * needed.
+ *
+ * Returns: (transfer full): the new custom event.
+ */
+GstEvent *
+gst_event_new_custom (GstEventType type, GstStructure * structure)
+{
+ GstEvent *event;
+
+ /* structure must not have a parent */
+ event = gst_event_new (type);
+ if (structure) {
+ if (!gst_structure_set_parent_refcount (structure,
+ &event->mini_object.refcount))
+ goto had_parent;
+
+ GST_EVENT_STRUCTURE (event) = structure;
+ }
+ return event;
+
+ /* ERRORS */
+had_parent:
+ {
+ gst_event_unref (event);
+ g_warning ("structure is already owned by another object");
+ return NULL;
+ }
+}
+
+/**
+ * gst_event_get_structure:
+ * @event: The #GstEvent.
+ *
+ * Access the structure of the event.
+ *
+ * Returns: The structure of the event. The structure is still
+ * owned by the event, which means that you should not free it and
+ * that the pointer becomes invalid when you free the event.
+ *
+ * MT safe.
+ */
+const GstStructure *
+gst_event_get_structure (GstEvent * event)
+{
+ g_return_val_if_fail (GST_IS_EVENT (event), NULL);
+
+ return GST_EVENT_STRUCTURE (event);
+}
+
+/**
+ * gst_event_writable_structure:
+ * @event: The #GstEvent.
+ *
+ * Get a writable version of the structure.
+ *
+ * Returns: The structure of the event. The structure is still
+ * owned by the event, which means that you should not free it and
+ * that the pointer becomes invalid when you free the event.
+ * This function checks if @event is writable and will never return NULL.
+ *
+ * MT safe.
+ */
+GstStructure *
+gst_event_writable_structure (GstEvent * event)
+{
+ GstStructure *structure;
+
+ g_return_val_if_fail (GST_IS_EVENT (event), NULL);
+ g_return_val_if_fail (gst_event_is_writable (event), NULL);
+
+ structure = GST_EVENT_STRUCTURE (event);
+
+ if (structure == NULL) {
+ structure =
+ gst_structure_id_empty_new (gst_event_type_to_quark (GST_EVENT_TYPE
+ (event)));
+ gst_structure_set_parent_refcount (structure, &event->mini_object.refcount);
+ GST_EVENT_STRUCTURE (event) = structure;
+ }
+ return structure;
+}
+
+/**
+ * gst_event_has_name:
+ * @event: The #GstEvent.
+ * @name: name to check
+ *
+ * Checks if @event has the given @name. This function is usually used to
+ * check the name of a custom event.
+ *
+ * Returns: %TRUE if @name matches the name of the event structure.
+ *
+ * Since: 0.10.20
+ */
+gboolean
+gst_event_has_name (GstEvent * event, const gchar * name)
+{
+ g_return_val_if_fail (GST_IS_EVENT (event), FALSE);
+
+ if (GST_EVENT_STRUCTURE (event) == NULL)
+ return FALSE;
+
+ return gst_structure_has_name (GST_EVENT_STRUCTURE (event), name);
+}
+
+/**
+ * gst_event_get_seqnum:
+ * @event: A #GstEvent.
+ *
+ * Retrieve the sequence number of a event.
+ *
+ * Events have ever-incrementing sequence numbers, which may also be set
+ * explicitly via gst_event_set_seqnum(). Sequence numbers are typically used to
+ * indicate that a event corresponds to some other set of events or messages,
+ * for example an EOS event corresponding to a SEEK event. It is considered good
+ * practice to make this correspondence when possible, though it is not
+ * required.
+ *
+ * Note that events and messages share the same sequence number incrementor;
+ * two events or messages will never have the same sequence number unless
+ * that correspondence was made explicitly.
+ *
+ * Returns: The event's sequence number.
+ *
+ * MT safe.
+ *
+ * Since: 0.10.22
+ */
+guint32
+gst_event_get_seqnum (GstEvent * event)
+{
+ g_return_val_if_fail (GST_IS_EVENT (event), -1);
+
+ return GST_EVENT_SEQNUM (event);
+}
+
+/**
+ * gst_event_set_seqnum:
+ * @event: A #GstEvent.
+ * @seqnum: A sequence number.
+ *
+ * Set the sequence number of a event.
+ *
+ * This function might be called by the creator of a event to indicate that the
+ * event relates to other events or messages. See gst_event_get_seqnum() for
+ * more information.
+ *
+ * MT safe.
+ *
+ * Since: 0.10.22
+ */
+void
+gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
+{
+ g_return_if_fail (GST_IS_EVENT (event));
+
+ GST_EVENT_SEQNUM (event) = seqnum;
+}
+
+/* FIXME 0.11: It would be nice to have flush events
+ * that don't reset the running time in the sinks
+ */
+
+/**
+ * gst_event_new_flush_start:
+ *
+ * Allocate a new flush start event. The flush start event can be sent
+ * upstream and downstream and travels out-of-bounds with the dataflow.
+ *
+ * It marks pads as being flushing and will make them return
+ * #GST_FLOW_WRONG_STATE when used for data flow with gst_pad_push(),
+ * gst_pad_chain(), gst_pad_alloc_buffer(), gst_pad_get_range() and
+ * gst_pad_pull_range(). Any event (except a #GST_EVENT_FLUSH_STOP) received
+ * on a flushing pad will return %FALSE immediately.
+ *
+ * Elements should unlock any blocking functions and exit their streaming
+ * functions as fast as possible when this event is received.
+ *
+ * This event is typically generated after a seek to flush out all queued data
+ * in the pipeline so that the new media is played as soon as possible.
+ *
+ * Returns: (transfer full): a new flush start event.
+ */
+GstEvent *
+gst_event_new_flush_start (void)
+{
+ return gst_event_new (GST_EVENT_FLUSH_START);
+}
+
+/**
+ * gst_event_new_flush_stop:
+ * @reset_time: if time should be reset
+ *
+ * Allocate a new flush stop event. The flush stop event can be sent
+ * upstream and downstream and travels serialized with the dataflow.
+ * It is typically sent after sending a FLUSH_START event to make the
+ * pads accept data again.
+ *
+ * Elements can process this event synchronized with the dataflow since
+ * the preceeding FLUSH_START event stopped the dataflow.
+ *
+ * This event is typically generated to complete a seek and to resume
+ * dataflow.
+ *
+ * Returns: (transfer full): a new flush stop event.
+ */
+GstEvent *
+gst_event_new_flush_stop (gboolean reset_time)
+{
+ GstEvent *event;
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating flush stop %d", reset_time);
+
+ event = gst_event_new_custom (GST_EVENT_FLUSH_STOP,
+ gst_structure_id_new (GST_QUARK (EVENT_FLUSH_STOP),
+ GST_QUARK (RESET_TIME), G_TYPE_BOOLEAN, reset_time, NULL));
+
+ return event;
+}
+
+/**
+ * gst_event_parse_flush_stop:
+ * @event: The event to parse
+ * @reset_time: (out): if time should be reset
+ *
+ * Parse the FLUSH_STOP event and retrieve the @reset_time member.
+ */
+void
+gst_event_parse_flush_stop (GstEvent * event, gboolean * reset_time)
+{
+ GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_FLUSH_STOP);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (G_LIKELY (reset_time))
+ *reset_time =
+ g_value_get_boolean (gst_structure_id_get_value (structure,
+ GST_QUARK (RESET_TIME)));
+}
+
+/**
+ * gst_event_new_eos:
+ *
+ * Create a new EOS event. The eos event can only travel downstream
+ * synchronized with the buffer flow. Elements that receive the EOS
+ * event on a pad can return #GST_FLOW_UNEXPECTED as a #GstFlowReturn
+ * when data after the EOS event arrives.
+ *
+ * The EOS event will travel down to the sink elements in the pipeline
+ * which will then post the #GST_MESSAGE_EOS on the bus after they have
+ * finished playing any buffered data.
+ *
+ * When all sinks have posted an EOS message, an EOS message is
+ * forwarded to the application.
+ *
+ * The EOS event itself will not cause any state transitions of the pipeline.
+ *
+ * Returns: (transfer full): the new EOS event.
+ */
+GstEvent *
+gst_event_new_eos (void)
+{
+ return gst_event_new (GST_EVENT_EOS);
+}
+
+/**
+ * gst_event_new_caps:
+ * @caps: a #GstCaps
+ *
+ * Create a new CAPS event for @caps. The caps event can only travel downstream
+ * synchronized with the buffer flow and contains the format of the buffers
+ * that will follow after the event.
+ *
+ * Returns: (transfer full): the new CAPS event.
+ */
+GstEvent *
+gst_event_new_caps (GstCaps * caps)
+{
+ GstEvent *event;
+
+ g_return_val_if_fail (caps != NULL, NULL);
+ g_return_val_if_fail (gst_caps_is_fixed (caps), NULL);
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating caps event %" GST_PTR_FORMAT, caps);
+
+ event = gst_event_new_custom (GST_EVENT_CAPS,
+ gst_structure_id_new (GST_QUARK (EVENT_CAPS),
+ GST_QUARK (CAPS), GST_TYPE_CAPS, caps, NULL));
+
+ return event;
+}
+
+/**
+ * gst_event_parse_caps:
+ * @event: The event to parse
+ * @caps: (out): A pointer to the caps
+ *
+ * Get the caps from @event. The caps remains valid as long as @event remains
+ * valid.
+ */
+void
+gst_event_parse_caps (GstEvent * event, GstCaps ** caps)
+{
+ GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_CAPS);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (G_LIKELY (caps))
+ *caps =
+ g_value_get_boxed (gst_structure_id_get_value (structure,
+ GST_QUARK (CAPS)));
+}
+
+/**
+ * gst_event_new_segment:
+ * @segment: a #GstSegment
+ *
+ * Create a new SEGMENT event for @segment. The segment event can only travel
+ * downstream synchronized with the buffer flow and contains timing information
+ * and playback properties for the buffers that will follow.
+ *
+ * The newsegment event marks the range of buffers to be processed. All
+ * data not within the segment range is not to be processed. This can be
+ * used intelligently by plugins to apply more efficient methods of skipping
+ * unneeded data. The valid range is expressed with the @start and @stop
+ * values.
+ *
+ * The time value of the segment is used in conjunction with the start
+ * value to convert the buffer timestamps into the stream time. This is
+ * usually done in sinks to report the current stream_time.
+ * @time represents the stream_time of a buffer carrying a timestamp of
+ * @start. @time cannot be -1.
+ *
+ * @start cannot be -1, @stop can be -1. If there
+ * is a valid @stop given, it must be greater or equal the @start, including
+ * when the indicated playback @rate is < 0.
+ *
+ * The @applied_rate value provides information about any rate adjustment that
+ * has already been made to the timestamps and content on the buffers of the
+ * stream. (@rate * @applied_rate) should always equal the rate that has been
+ * requested for playback. For example, if an element has an input segment
+ * with intended playback @rate of 2.0 and applied_rate of 1.0, it can adjust
+ * incoming timestamps and buffer content by half and output a newsegment event
+ * with @rate of 1.0 and @applied_rate of 2.0
+ *
+ * After a newsegment event, the buffer stream time is calculated with:
+ *
+ * time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
+ *
+ * Returns: (transfer full): the new SEGMENT event.
+ */
+GstEvent *
+gst_event_new_segment (GstSegment * segment)
+{
+ GstEvent *event;
+
+ g_return_val_if_fail (segment != NULL, NULL);
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
+ segment);
+
+ event = gst_event_new_custom (GST_EVENT_SEGMENT,
+ gst_structure_id_new (GST_QUARK (EVENT_SEGMENT),
+ GST_QUARK (SEGMENT), GST_TYPE_SEGMENT, segment, NULL));
+
+ return event;
+}
+
+/**
+ * gst_event_parse_segment:
+ * @event: The event to parse
+ * @segment: (out) (transfer none): a pointer to a #GstSegment
+ *
+ * Parses a segment @event and stores the result in the given @segment location.
+ * @segment remains valid only until the @event is freed. Don't modify the segment
+ * and make a copy if you want to modify it or store it for later use.
+ */
+void
+gst_event_parse_segment (GstEvent * event, const GstSegment ** segment)
+{
+ GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
+
+ if (segment) {
+ structure = GST_EVENT_STRUCTURE (event);
+ *segment = g_value_get_boxed (gst_structure_id_get_value (structure,
+ GST_QUARK (SEGMENT)));
+ }
+}
+
+/**
+ * gst_event_copy_segment:
+ * @event: The event to parse
+ * @segment: a pointer to a #GstSegment
+ *
+ * Parses a segment @event and copies the #GstSegment into the location
+ * given by @segment.
+ */
+void
+gst_event_copy_segment (GstEvent * event, GstSegment * segment)
+{
+ const GstSegment *src;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT);
+
+ if (segment) {
+ gst_event_parse_segment (event, &src);
+ gst_segment_copy_into (src, segment);
+ }
+}
+
+/**
+ * gst_event_new_tag:
+ * @taglist: (transfer full): metadata list. The event will take ownership
+ * of the taglist.
+ *
+ * Generates a metadata tag event from the given @taglist.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ */
+GstEvent *
+gst_event_new_tag (GstTagList * taglist)
+{
+ g_return_val_if_fail (taglist != NULL, NULL);
+
+ return gst_event_new_custom (GST_EVENT_TAG, (GstStructure *) taglist);
+}
+
+/**
+ * gst_event_parse_tag:
+ * @event: a tag event
+ * @taglist: (out) (transfer none): pointer to metadata list
+ *
+ * Parses a tag @event and stores the results in the given @taglist location.
+ * No reference to the taglist will be returned, it remains valid only until
+ * the @event is freed. Don't modify or free the taglist, make a copy if you
+ * want to modify it or store it for later use.
+ */
+void
+gst_event_parse_tag (GstEvent * event, GstTagList ** taglist)
+{
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
+
+ if (taglist)
+ *taglist = (GstTagList *) GST_EVENT_STRUCTURE (event);
+}
+
+/* buffersize event */
+/**
+ * gst_event_new_buffer_size:
+ * @format: buffer format
+ * @minsize: minimum buffer size
+ * @maxsize: maximum buffer size
+ * @async: thread behavior
+ *
+ * Create a new buffersize event. The event is sent downstream and notifies
+ * elements that they should provide a buffer of the specified dimensions.
+ *
+ * When the @async flag is set, a thread boundary is preferred.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ */
+GstEvent *
+gst_event_new_buffer_size (GstFormat format, gint64 minsize,
+ gint64 maxsize, gboolean async)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ GST_CAT_INFO (GST_CAT_EVENT,
+ "creating buffersize format %s, minsize %" G_GINT64_FORMAT
+ ", maxsize %" G_GINT64_FORMAT ", async %d", gst_format_get_name (format),
+ minsize, maxsize, async);
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_BUFFER_SIZE),
+ GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+ GST_QUARK (MINSIZE), G_TYPE_INT64, minsize,
+ GST_QUARK (MAXSIZE), G_TYPE_INT64, maxsize,
+ GST_QUARK (ASYNC), G_TYPE_BOOLEAN, async, NULL);
+ event = gst_event_new_custom (GST_EVENT_BUFFERSIZE, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_buffer_size:
+ * @event: The event to query
+ * @format: (out): A pointer to store the format in
+ * @minsize: (out): A pointer to store the minsize in
+ * @maxsize: (out): A pointer to store the maxsize in
+ * @async: (out): A pointer to store the async-flag in
+ *
+ * Get the format, minsize, maxsize and async-flag in the buffersize event.
+ */
+void
+gst_event_parse_buffer_size (GstEvent * event, GstFormat * format,
+ gint64 * minsize, gint64 * maxsize, gboolean * async)
+{
+ const GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_BUFFERSIZE);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (format)
+ *format = (GstFormat)
+ g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (FORMAT)));
+ if (minsize)
+ *minsize =
+ g_value_get_int64 (gst_structure_id_get_value (structure,
+ GST_QUARK (MINSIZE)));
+ if (maxsize)
+ *maxsize =
+ g_value_get_int64 (gst_structure_id_get_value (structure,
+ GST_QUARK (MAXSIZE)));
+ if (async)
+ *async =
+ g_value_get_boolean (gst_structure_id_get_value (structure,
+ GST_QUARK (ASYNC)));
+}
+
+/**
+ * gst_event_new_qos:
+ * @type: the QoS type
+ * @proportion: the proportion of the qos message
+ * @diff: The time difference of the last Clock sync
+ * @timestamp: The timestamp of the buffer
+ *
+ * Allocate a new qos event with the given values.
+ * The QOS event is generated in an element that wants an upstream
+ * element to either reduce or increase its rate because of
+ * high/low CPU load or other resource usage such as network performance or
+ * throttling. Typically sinks generate these events for each buffer
+ * they receive.
+ *
+ * @type indicates the reason for the QoS event. #GST_QOS_TYPE_OVERFLOW is
+ * used when a buffer arrived in time or when the sink cannot keep up with
+ * the upstream datarate. #GST_QOS_TYPE_UNDERFLOW is when the sink is not
+ * receiving buffers fast enough and thus has to drop late buffers.
+ * #GST_QOS_TYPE_THROTTLE is used when the datarate is artificially limited
+ * by the application, for example to reduce power consumption.
+ *
+ * @proportion indicates the real-time performance of the streaming in the
+ * element that generated the QoS event (usually the sink). The value is
+ * generally computed based on more long term statistics about the streams
+ * timestamps compared to the clock.
+ * A value < 1.0 indicates that the upstream element is producing data faster
+ * than real-time. A value > 1.0 indicates that the upstream element is not
+ * producing data fast enough. 1.0 is the ideal @proportion value. The
+ * proportion value can safely be used to lower or increase the quality of
+ * the element.
+ *
+ * @diff is the difference against the clock in running time of the last
+ * buffer that caused the element to generate the QOS event. A negative value
+ * means that the buffer with @timestamp arrived in time. A positive value
+ * indicates how late the buffer with @timestamp was. When throttling is
+ * enabled, @diff will be set to the requested throttling interval.
+ *
+ * @timestamp is the timestamp of the last buffer that cause the element
+ * to generate the QOS event. It is expressed in running time and thus an ever
+ * increasing value.
+ *
+ * The upstream element can use the @diff and @timestamp values to decide
+ * whether to process more buffers. For possitive @diff, all buffers with
+ * timestamp <= @timestamp + @diff will certainly arrive late in the sink
+ * as well. A (negative) @diff value so that @timestamp + @diff would yield a
+ * result smaller than 0 is not allowed.
+ *
+ * The application can use general event probes to intercept the QoS
+ * event and implement custom application specific QoS handling.
+ *
+ * Returns: (transfer full): a new QOS event.
+ */
+GstEvent *
+gst_event_new_qos (GstQOSType type, gdouble proportion,
+ GstClockTimeDiff diff, GstClockTime timestamp)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ /* diff must be positive or timestamp + diff must be positive */
+ g_return_val_if_fail (diff >= 0 || -diff <= timestamp, NULL);
+
+ GST_CAT_INFO (GST_CAT_EVENT,
+ "creating qos type %d, proportion %lf, diff %" G_GINT64_FORMAT
+ ", timestamp %" GST_TIME_FORMAT, type, proportion,
+ diff, GST_TIME_ARGS (timestamp));
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_QOS),
+ GST_QUARK (TYPE), GST_TYPE_QOS_TYPE, type,
+ GST_QUARK (PROPORTION), G_TYPE_DOUBLE, proportion,
+ GST_QUARK (DIFF), G_TYPE_INT64, diff,
+ GST_QUARK (TIMESTAMP), G_TYPE_UINT64, timestamp, NULL);
+ event = gst_event_new_custom (GST_EVENT_QOS, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_qos:
+ * @event: The event to query
+ * @type: (out): A pointer to store the QoS type in
+ * @proportion: (out): A pointer to store the proportion in
+ * @diff: (out): A pointer to store the diff in
+ * @timestamp: (out): A pointer to store the timestamp in
+ *
+ * Get the type, proportion, diff and timestamp in the qos event. See
+ * gst_event_new_qos() for more information about the different QoS values.
+ */
+void
+gst_event_parse_qos (GstEvent * event, GstQOSType * type,
+ gdouble * proportion, GstClockTimeDiff * diff, GstClockTime * timestamp)
+{
+ const GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_QOS);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (type)
+ *type = (GstQOSType)
+ g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (TYPE)));
+ if (proportion)
+ *proportion =
+ g_value_get_double (gst_structure_id_get_value (structure,
+ GST_QUARK (PROPORTION)));
+ if (diff)
+ *diff =
+ g_value_get_int64 (gst_structure_id_get_value (structure,
+ GST_QUARK (DIFF)));
+ if (timestamp)
+ *timestamp =
+ g_value_get_uint64 (gst_structure_id_get_value (structure,
+ GST_QUARK (TIMESTAMP)));
+}
+
+/**
+ * gst_event_new_seek:
+ * @rate: The new playback rate
+ * @format: The format of the seek values
+ * @flags: The optional seek flags
+ * @start_type: The type and flags for the new start position
+ * @start: The value of the new start position
+ * @stop_type: The type and flags for the new stop position
+ * @stop: The value of the new stop position
+ *
+ * Allocate a new seek event with the given parameters.
+ *
+ * The seek event configures playback of the pipeline between @start to @stop
+ * at the speed given in @rate, also called a playback segment.
+ * The @start and @stop values are expressed in @format.
+ *
+ * A @rate of 1.0 means normal playback rate, 2.0 means double speed.
+ * Negatives values means backwards playback. A value of 0.0 for the
+ * rate is not allowed and should be accomplished instead by PAUSING the
+ * pipeline.
+ *
+ * A pipeline has a default playback segment configured with a start
+ * position of 0, a stop position of -1 and a rate of 1.0. The currently
+ * configured playback segment can be queried with #GST_QUERY_SEGMENT.
+ *
+ * @start_type and @stop_type specify how to adjust the currently configured
+ * start and stop fields in playback segment. Adjustments can be made relative
+ * or absolute to the last configured values. A type of #GST_SEEK_TYPE_NONE
+ * means that the position should not be updated.
+ *
+ * When the rate is positive and @start has been updated, playback will start
+ * from the newly configured start position.
+ *
+ * For negative rates, playback will start from the newly configured stop
+ * position (if any). If the stop position if updated, it must be different from
+ * -1 for negative rates.
+ *
+ * It is not possible to seek relative to the current playback position, to do
+ * this, PAUSE the pipeline, query the current playback position with
+ * #GST_QUERY_POSITION and update the playback segment current position with a
+ * #GST_SEEK_TYPE_SET to the desired position.
+ *
+ * Returns: (transfer full): a new seek event.
+ */
+GstEvent *
+gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
+ GstSeekType start_type, gint64 start, GstSeekType stop_type, gint64 stop)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ g_return_val_if_fail (rate != 0.0, NULL);
+
+ if (format == GST_FORMAT_TIME) {
+ GST_CAT_INFO (GST_CAT_EVENT,
+ "creating seek rate %lf, format TIME, flags %d, "
+ "start_type %d, start %" GST_TIME_FORMAT ", "
+ "stop_type %d, stop %" GST_TIME_FORMAT,
+ rate, flags, start_type, GST_TIME_ARGS (start),
+ stop_type, GST_TIME_ARGS (stop));
+ } else {
+ GST_CAT_INFO (GST_CAT_EVENT,
+ "creating seek rate %lf, format %s, flags %d, "
+ "start_type %d, start %" G_GINT64_FORMAT ", "
+ "stop_type %d, stop %" G_GINT64_FORMAT,
+ rate, gst_format_get_name (format), flags, start_type, start, stop_type,
+ stop);
+ }
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_SEEK),
+ GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
+ GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+ GST_QUARK (FLAGS), GST_TYPE_SEEK_FLAGS, flags,
+ GST_QUARK (CUR_TYPE), GST_TYPE_SEEK_TYPE, start_type,
+ GST_QUARK (CUR), G_TYPE_INT64, start,
+ GST_QUARK (STOP_TYPE), GST_TYPE_SEEK_TYPE, stop_type,
+ GST_QUARK (STOP), G_TYPE_INT64, stop, NULL);
+ event = gst_event_new_custom (GST_EVENT_SEEK, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_seek:
+ * @event: a seek event
+ * @rate: (out): result location for the rate
+ * @format: (out): result location for the stream format
+ * @flags: (out): result location for the #GstSeekFlags
+ * @start_type: (out): result location for the #GstSeekType of the start position
+ * @start: (out): result location for the start postion expressed in @format
+ * @stop_type: (out): result location for the #GstSeekType of the stop position
+ * @stop: (out): result location for the stop postion expressed in @format
+ *
+ * Parses a seek @event and stores the results in the given result locations.
+ */
+void
+gst_event_parse_seek (GstEvent * event, gdouble * rate,
+ GstFormat * format, GstSeekFlags * flags, GstSeekType * start_type,
+ gint64 * start, GstSeekType * stop_type, gint64 * stop)
+{
+ const GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEEK);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (rate)
+ *rate =
+ g_value_get_double (gst_structure_id_get_value (structure,
+ GST_QUARK (RATE)));
+ if (format)
+ *format = (GstFormat)
+ g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (FORMAT)));
+ if (flags)
+ *flags = (GstSeekFlags)
+ g_value_get_flags (gst_structure_id_get_value (structure,
+ GST_QUARK (FLAGS)));
+ if (start_type)
+ *start_type = (GstSeekType)
+ g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (CUR_TYPE)));
+ if (start)
+ *start =
+ g_value_get_int64 (gst_structure_id_get_value (structure,
+ GST_QUARK (CUR)));
+ if (stop_type)
+ *stop_type = (GstSeekType)
+ g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (STOP_TYPE)));
+ if (stop)
+ *stop =
+ g_value_get_int64 (gst_structure_id_get_value (structure,
+ GST_QUARK (STOP)));
+}
+
+/**
+ * gst_event_new_navigation:
+ * @structure: (transfer full): description of the event. The event will take
+ * ownership of the structure.
+ *
+ * Create a new navigation event from the given description.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ */
+GstEvent *
+gst_event_new_navigation (GstStructure * structure)
+{
+ g_return_val_if_fail (structure != NULL, NULL);
+
+ return gst_event_new_custom (GST_EVENT_NAVIGATION, structure);
+}
+
+/**
+ * gst_event_new_latency:
+ * @latency: the new latency value
+ *
+ * Create a new latency event. The event is sent upstream from the sinks and
+ * notifies elements that they should add an additional @latency to the
+ * running time before synchronising against the clock.
+ *
+ * The latency is mostly used in live sinks and is always expressed in
+ * the time format.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ *
+ * Since: 0.10.12
+ */
+GstEvent *
+gst_event_new_latency (GstClockTime latency)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ GST_CAT_INFO (GST_CAT_EVENT,
+ "creating latency event %" GST_TIME_FORMAT, GST_TIME_ARGS (latency));
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_LATENCY),
+ GST_QUARK (LATENCY), G_TYPE_UINT64, latency, NULL);
+ event = gst_event_new_custom (GST_EVENT_LATENCY, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_latency:
+ * @event: The event to query
+ * @latency: (out): A pointer to store the latency in.
+ *
+ * Get the latency in the latency event.
+ *
+ * Since: 0.10.12
+ */
+void
+gst_event_parse_latency (GstEvent * event, GstClockTime * latency)
+{
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_LATENCY);
+
+ if (latency)
+ *latency =
+ g_value_get_uint64 (gst_structure_id_get_value (GST_EVENT_STRUCTURE
+ (event), GST_QUARK (LATENCY)));
+}
+
+/**
+ * gst_event_new_step:
+ * @format: the format of @amount
+ * @amount: the amount of data to step
+ * @rate: the step rate
+ * @flush: flushing steps
+ * @intermediate: intermediate steps
+ *
+ * Create a new step event. The purpose of the step event is to instruct a sink
+ * to skip @amount (expressed in @format) of media. It can be used to implement
+ * stepping through the video frame by frame or for doing fast trick modes.
+ *
+ * A rate of <= 0.0 is not allowed, pause the pipeline or reverse the playback
+ * direction of the pipeline to get the same effect.
+ *
+ * The @flush flag will clear any pending data in the pipeline before starting
+ * the step operation.
+ *
+ * The @intermediate flag instructs the pipeline that this step operation is
+ * part of a larger step operation.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ *
+ * Since: 0.10.24
+ */
+GstEvent *
+gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
+ gboolean flush, gboolean intermediate)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ g_return_val_if_fail (rate > 0.0, NULL);
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating step event");
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_STEP),
+ GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
+ GST_QUARK (AMOUNT), G_TYPE_UINT64, amount,
+ GST_QUARK (RATE), G_TYPE_DOUBLE, rate,
+ GST_QUARK (FLUSH), G_TYPE_BOOLEAN, flush,
+ GST_QUARK (INTERMEDIATE), G_TYPE_BOOLEAN, intermediate, NULL);
+ event = gst_event_new_custom (GST_EVENT_STEP, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_step:
+ * @event: The event to query
+ * @format: (out) (allow-none): a pointer to store the format in
+ * @amount: (out) (allow-none): a pointer to store the amount in
+ * @rate: (out) (allow-none): a pointer to store the rate in
+ * @flush: (out) (allow-none): a pointer to store the flush boolean in
+ * @intermediate: (out) (allow-none): a pointer to store the intermediate
+ * boolean in
+ *
+ * Parse the step event.
+ *
+ * Since: 0.10.24
+ */
+void
+gst_event_parse_step (GstEvent * event, GstFormat * format, guint64 * amount,
+ gdouble * rate, gboolean * flush, gboolean * intermediate)
+{
+ const GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STEP);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (format)
+ *format =
+ (GstFormat) g_value_get_enum (gst_structure_id_get_value (structure,
+ GST_QUARK (FORMAT)));
+ if (amount)
+ *amount = g_value_get_uint64 (gst_structure_id_get_value (structure,
+ GST_QUARK (AMOUNT)));
+ if (rate)
+ *rate = g_value_get_double (gst_structure_id_get_value (structure,
+ GST_QUARK (RATE)));
+ if (flush)
+ *flush = g_value_get_boolean (gst_structure_id_get_value (structure,
+ GST_QUARK (FLUSH)));
+ if (intermediate)
+ *intermediate = g_value_get_boolean (gst_structure_id_get_value (structure,
+ GST_QUARK (INTERMEDIATE)));
+}
+
+/**
+ * gst_event_new_reconfigure:
+
+ * Create a new reconfigure event. The purpose of the reconfingure event is
+ * to travel upstream and make elements renegotiate their caps or reconfigure
+ * their buffer pools. This is useful when changing properties on elements
+ * or changing the topology of the pipeline.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ *
+ * Since: 0.11.0
+ */
+GstEvent *
+gst_event_new_reconfigure (void)
+{
+ GstEvent *event;
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating reconfigure event");
+
+ event = gst_event_new_custom (GST_EVENT_RECONFIGURE, NULL);
+
+ return event;
+}
+
+/**
+ * gst_event_new_sink_message:
+ * @msg: (transfer none): the #GstMessage to be posted
+ *
+ * Create a new sink-message event. The purpose of the sink-message event is
+ * to instruct a sink to post the message contained in the event synchronized
+ * with the stream.
+ *
+ * Returns: (transfer full): a new #GstEvent
+ *
+ * Since: 0.10.26
+ */
+/* FIXME 0.11: take ownership of msg for consistency? */
+GstEvent *
+gst_event_new_sink_message (GstMessage * msg)
+{
+ GstEvent *event;
+ GstStructure *structure;
+
+ g_return_val_if_fail (msg != NULL, NULL);
+
+ GST_CAT_INFO (GST_CAT_EVENT, "creating sink-message event");
+
+ structure = gst_structure_id_new (GST_QUARK (EVENT_SINK_MESSAGE),
+ GST_QUARK (MESSAGE), GST_TYPE_MESSAGE, msg, NULL);
+ event = gst_event_new_custom (GST_EVENT_SINK_MESSAGE, structure);
+
+ return event;
+}
+
+/**
+ * gst_event_parse_sink_message:
+ * @event: The event to query
+ * @msg: (out) (transfer full): a pointer to store the #GstMessage in.
+ *
+ * Parse the sink-message event. Unref @msg after usage.
+ *
+ * Since: 0.10.26
+ */
+void
+gst_event_parse_sink_message (GstEvent * event, GstMessage ** msg)
+{
+ const GstStructure *structure;
+
+ g_return_if_fail (GST_IS_EVENT (event));
+ g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SINK_MESSAGE);
+
+ structure = GST_EVENT_STRUCTURE (event);
+ if (msg)
+ *msg =
+ GST_MESSAGE (g_value_dup_boxed (gst_structure_id_get_value
+ (structure, GST_QUARK (MESSAGE))));
+}
