/* 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstevent
* @title: 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.
* |[<!-- language="C" -->
* 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");
* ...
* ]|
*/
#include "gst_private.h"
#include <string.h> /* memcpy */
#include "gstinfo.h"
#include "gstevent.h"
#include "gstenumtypes.h"
#include "gstutils.h"
#include "gstquark.h"
#include "gstvalue.h"
GType _gst_event_type = 0;
typedef struct
{
GstEvent event;
GstStructure *structure;
gint64 running_time_offset;
} 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_SELECT_STREAMS, "select-streams", 0},
{GST_EVENT_STREAM_START, "stream-start", 0},
{GST_EVENT_STREAM_COLLECTION, "stream-collection", 0},
{GST_EVENT_CAPS, "caps", 0},
{GST_EVENT_SEGMENT, "segment", 0},
{GST_EVENT_TAG, "tag", 0},
{GST_EVENT_TOC, "toc", 0},
{GST_EVENT_PROTECTION, "protection", 0},
{GST_EVENT_BUFFERSIZE, "buffersize", 0},
{GST_EVENT_SINK_MESSAGE, "sink-message", 0},
{GST_EVENT_EOS, "eos", 0},
{GST_EVENT_SEGMENT_DONE, "segment-done", 0},
{GST_EVENT_GAP, "gap", 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_TOC_SELECT, "toc-select", 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_DOWNSTREAM_STICKY, "custom-downstream-sticky", 0},
{GST_EVENT_CUSTOM_BOTH, "custom-both", 0},
{GST_EVENT_CUSTOM_BOTH_OOB, "custom-both-oob", 0},
{GST_EVENT_STREAM_GROUP_DONE, "stream-group-done", 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_NUM_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 (sizeof (GstEventImpl), event);
}
static void gst_event_init (GstEventImpl * event, GstEventType type);
static GstEvent *
_gst_event_copy (GstEvent * event)
{
GstEventImpl *copy;
GstStructure *s;
copy = g_slice_new0 (GstEventImpl);
gst_event_init (copy, 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);
} else {
GST_EVENT_STRUCTURE (copy) = NULL;
}
((GstEventImpl *) copy)->running_time_offset =
((GstEventImpl *) event)->running_time_offset;
return GST_EVENT_CAST (copy);
}
static void
gst_event_init (GstEventImpl * event, GstEventType type)
{
gst_mini_object_init (GST_MINI_OBJECT_CAST (event), 0, _gst_event_type,
(GstMiniObjectCopyFunction) _gst_event_copy, NULL,
(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 ();
event->running_time_offset = 0;
}
/**
* 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) (nullable): the new custom event.
*/
GstEvent *
gst_event_new_custom (GstEventType type, GstStructure * structure)
{
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);
if (structure) {
/* structure must not have a parent */
if (!gst_structure_set_parent_refcount (structure,
&event->event.mini_object.refcount))
goto had_parent;
}
gst_event_init (event, type);
GST_EVENT_STRUCTURE (event) = structure;
return GST_EVENT_CAST (event);
/* ERRORS */
had_parent:
{
g_slice_free1 (sizeof (GstEventImpl), 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: (transfer none) (nullable): 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: (transfer none): 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_new_id_empty (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.
*/
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.
*/
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.
*/
void
gst_event_set_seqnum (GstEvent * event, guint32 seqnum)
{
g_return_if_fail (GST_IS_EVENT (event));
GST_EVENT_SEQNUM (event) = seqnum;
}
/**
* gst_event_get_running_time_offset:
* @event: A #GstEvent.
*
* Retrieve the accumulated running time offset of the event.
*
* Events passing through #GstPads that have a running time
* offset set via gst_pad_set_offset() will get their offset
* adjusted according to the pad's offset.
*
* If the event contains any information that related to the
* running time, this information will need to be updated
* before usage with this offset.
*
* Returns: The event's running time offset
*
* MT safe.
*
* Since: 1.4
*/
gint64
gst_event_get_running_time_offset (GstEvent * event)
{
g_return_val_if_fail (GST_IS_EVENT (event), 0);
return ((GstEventImpl *) event)->running_time_offset;
}
/**
* gst_event_set_running_time_offset:
* @event: A #GstEvent.
* @offset: A the new running time offset
*
* Set the running time offset of a event. See
* gst_event_get_running_time_offset() for more information.
*
* MT safe.
*
* Since: 1.4
*/
void
gst_event_set_running_time_offset (GstEvent * event, gint64 offset)
{
g_return_if_fail (GST_IS_EVENT (event));
((GstEventImpl *) event)->running_time_offset = offset;
}
/**
* 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_FLUSHING when used for data flow with gst_pad_push(),
* gst_pad_chain(), 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_custom (GST_EVENT_FLUSH_START, NULL);
}
/**
* 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 preceding 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_new_id (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_select_streams:
* @streams: (element-type utf8) (transfer none): the list of streams to
* activate
*
* Allocate a new select-streams event.
*
* The select-streams event requests the specified @streams to be activated.
*
* The list of @streams corresponds to the "Stream ID" of each stream to be
* activated. Those ID can be obtained via the #GstStream objects present
* in #GST_EVENT_STREAM_START, #GST_EVENT_STREAM_COLLECTION or
* #GST_MESSAGE_STREAM_COLLECTION.
*
* Note: The list of @streams can not be empty.
*
* Returns: (transfer full): a new select-streams event or %NULL in case of
* an error (like an empty streams list).
*
* Since: 1.10
*/
GstEvent *
gst_event_new_select_streams (GList * streams)
{
GstEvent *event;
GValue val = G_VALUE_INIT;
GstStructure *struc;
GList *tmpl;
g_return_val_if_fail (streams != NULL, NULL);
GST_CAT_INFO (GST_CAT_EVENT, "Creating new select-streams event");
struc = gst_structure_new_id_empty (GST_QUARK (EVENT_SELECT_STREAMS));
g_value_init (&val, GST_TYPE_LIST);
/* Fill struc with streams */
for (tmpl = streams; tmpl; tmpl = tmpl->next) {
GValue strval = G_VALUE_INIT;
const gchar *str = (const gchar *) tmpl->data;
g_value_init (&strval, G_TYPE_STRING);
g_value_set_string (&strval, str);
gst_value_list_append_and_take_value (&val, &strval);
}
gst_structure_id_take_value (struc, GST_QUARK (STREAMS), &val);
event = gst_event_new_custom (GST_EVENT_SELECT_STREAMS, struc);
return event;
}
/**
* gst_event_parse_select_streams:
* @event: The event to parse
* @streams: (out) (element-type utf8) (transfer full): the streams
*
* Parse the SELECT_STREAMS event and retrieve the contained streams.
*
* Since: 1.10
*/
void
gst_event_parse_select_streams (GstEvent * event, GList ** streams)
{
GstStructure *structure;
GList *res = NULL;
g_return_if_fail (GST_IS_EVENT (event));
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SELECT_STREAMS);
structure = GST_EVENT_STRUCTURE (event);
if (G_LIKELY (streams)) {
const GValue *vlist =
gst_structure_id_get_value (structure, GST_QUARK (STREAMS));
guint i, sz = gst_value_list_get_size (vlist);
for (i = 0; i < sz; i++) {
const GValue *strv = gst_value_list_get_value (vlist, i);
res = g_list_append (res, g_value_dup_string (strv));
}
*streams = res;
}
}
/**
* gst_event_new_stream_group_done:
* @group_id: the group id of the stream group which is ending
*
* Create a new Stream Group Done event. The stream-group-done event can
* only travel downstream synchronized with the buffer flow. Elements
* that receive the event on a pad should handle it mostly like EOS,
* and emit any data or pending buffers that would depend on more data
* arriving and unblock, since there won't be any more data.
*
* This event is followed by EOS at some point in the future, and is
* generally used when switching pads - to unblock downstream so that
* new pads can be exposed before sending EOS on the existing pads.
*
* Returns: (transfer full): the new stream-group-done event.
*
* Since: 1.10
*/
GstEvent *
gst_event_new_stream_group_done (guint group_id)
{
GstStructure *s;
s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_GROUP_DONE),
GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
return gst_event_new_custom (GST_EVENT_STREAM_GROUP_DONE, s);
}
/**
* gst_event_parse_stream_group_done:
* @event: a stream-group-done event.
* @group_id: (out): address of variable to store the group id into
*
* Parse a stream-group-done @event and store the result in the given
* @group_id location.
*
* Since: 1.10
*/
void
gst_event_parse_stream_group_done (GstEvent * event, guint * group_id)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_GROUP_DONE);
if (group_id) {
gst_structure_id_get (GST_EVENT_STRUCTURE (event),
GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
}
}
/**
* 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_EOS 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_custom (GST_EVENT_EOS, NULL);
}
/**
* gst_event_new_gap:
* @timestamp: the start time (pts) of the gap
* @duration: the duration of the gap
*
* Create a new GAP event. A gap event can be thought of as conceptually
* equivalent to a buffer to signal that there is no data for a certain
* amount of time. This is useful to signal a gap to downstream elements
* which may wait for data, such as muxers or mixers or overlays, especially
* for sparse streams such as subtitle streams.
*
* Returns: (transfer full): the new GAP event.
*/
GstEvent *
gst_event_new_gap (GstClockTime timestamp, GstClockTime duration)
{
GstEvent *event;
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (timestamp), NULL);
GST_CAT_TRACE (GST_CAT_EVENT, "creating gap %" GST_TIME_FORMAT " - "
"%" GST_TIME_FORMAT " (duration: %" GST_TIME_FORMAT ")",
GST_TIME_ARGS (timestamp), GST_TIME_ARGS (timestamp + duration),
GST_TIME_ARGS (duration));
event = gst_event_new_custom (GST_EVENT_GAP,
gst_structure_new_id (GST_QUARK (EVENT_GAP),
GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL));
return event;
}
/**
* gst_event_parse_gap:
* @event: a #GstEvent of type #GST_EVENT_GAP
* @timestamp: (out) (allow-none): location where to store the
* start time (pts) of the gap, or %NULL
* @duration: (out) (allow-none): location where to store the duration of
* the gap, or %NULL
*
* Extract timestamp and duration from a new GAP event.
*/
void
gst_event_parse_gap (GstEvent * event, GstClockTime * timestamp,
GstClockTime * duration)
{
GstStructure *structure;
g_return_if_fail (GST_IS_EVENT (event));
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_GAP);
structure = GST_EVENT_STRUCTURE (event);
gst_structure_id_get (structure,
GST_QUARK (TIMESTAMP), GST_TYPE_CLOCK_TIME, timestamp,
GST_QUARK (DURATION), GST_TYPE_CLOCK_TIME, duration, NULL);
}
/**
* gst_event_new_caps:
* @caps: (transfer none): 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) (nullable): 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_new_id (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) (transfer none): 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: (transfer none): 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 segment 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 segment event
* with @rate of 1.0 and @applied_rate of 2.0
*
* After a segment event, the buffer stream time is calculated with:
*
* time + (TIMESTAMP(buf) - start) * ABS (rate * applied_rate)
*
* Returns: (transfer full) (nullable): the new SEGMENT event.
*/
GstEvent *
gst_event_new_segment (const GstSegment * segment)
{
GstEvent *event;
g_return_val_if_fail (segment != NULL, NULL);
g_return_val_if_fail (segment->rate != 0.0, NULL);
g_return_val_if_fail (segment->applied_rate != 0.0, NULL);
g_return_val_if_fail (segment->format != GST_FORMAT_UNDEFINED, NULL);
GST_CAT_INFO (GST_CAT_EVENT, "creating segment event %" GST_SEGMENT_FORMAT,
segment);
event = gst_event_new_custom (GST_EVENT_SEGMENT,
gst_structure_new_id (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.
*
* The scope of the taglist specifies if the taglist applies to the
* complete medium or only to this specific stream. As the tag event
* is a sticky event, elements should merge tags received from
* upstream with a given scope with their own tags with the same
* scope and create a new tag event from it.
*
* Returns: (transfer full): a new #GstEvent
*/
GstEvent *
gst_event_new_tag (GstTagList * taglist)
{
GstStructure *s;
GValue val = G_VALUE_INIT;
const gchar *names[] = { "GstTagList-stream", "GstTagList-global" };
g_return_val_if_fail (taglist != NULL, NULL);
s = gst_structure_new_empty (names[gst_tag_list_get_scope (taglist)]);
g_value_init (&val, GST_TYPE_TAG_LIST);
g_value_take_boxed (&val, taglist);
gst_structure_id_take_value (s, GST_QUARK (TAGLIST), &val);
return gst_event_new_custom (GST_EVENT_TAG, s);
}
/**
* 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)
{
const GValue *val;
g_return_if_fail (GST_IS_EVENT (event));
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TAG);
val = gst_structure_id_get_value (GST_EVENT_STRUCTURE (event),
GST_QUARK (TAGLIST));
if (taglist)
*taglist = (GstTagList *) g_value_get_boxed (val);
}
/* 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_new_id (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 positive @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) (nullable): 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_LOG (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_new_id (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.
*
* @timestamp will be adjusted for any pad offsets of pads it was passing through.
*/
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) {
gint64 offset = gst_event_get_running_time_offset (event);
GstClockTimeDiff diff_ =
g_value_get_int64 (gst_structure_id_get_value (structure,
GST_QUARK (DIFF)));
*timestamp =
g_value_get_uint64 (gst_structure_id_get_value (structure,
GST_QUARK (TIMESTAMP)));
/* Catch underflows */
if (*timestamp > -offset)
*timestamp += offset;
else
*timestamp = 0;
/* Make sure that timestamp + diff is always >= 0. Because
* of the running time offset this might not be true */
if (diff_ < 0 && *timestamp < -diff_)
*timestamp = (GstClockTime) - diff_;
}
}
/**
* 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 is updated, it must be different from
* -1 (#GST_CLOCK_TIME_NONE) 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) (nullable): 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_new_id (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 position expressed in @format
* @stop_type: (out): result location for the #GstSeekType of the stop position
* @stop: (out): result location for the stop position 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
*/
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_new_id (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.
*/
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, for the effect of rate
* = 0.0 or first reverse the direction of playback using a seek event to get
* the same effect as rate < 0.0.
*
* 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) (nullable): a new #GstEvent
*/
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_new_id (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.
*/
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 reconfigure 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
*/
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:
* @name: a name for the event
* @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.
*
* @name is used to store multiple sticky events on one pad.
*
* Returns: (transfer full): a new #GstEvent
*/
/* FIXME 2.0: take ownership of msg for consistency? */
GstEvent *
gst_event_new_sink_message (const gchar * name, 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_new_id (g_quark_from_string (name),
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.
*/
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))));
}
/**
* gst_event_new_stream_start:
* @stream_id: Identifier for this stream
*
* Create a new STREAM_START event. The stream start event can only
* travel downstream synchronized with the buffer flow. It is expected
* to be the first event that is sent for a new stream.
*
* Source elements, demuxers and other elements that create new streams
* are supposed to send this event as the first event of a new stream. It
* should not be sent after a flushing seek or in similar situations
* and is used to mark the beginning of a new logical stream. Elements
* combining multiple streams must ensure that this event is only forwarded
* downstream once and not for every single input stream.
*
* The @stream_id should be a unique string that consists of the upstream
* stream-id, / as separator and a unique stream-id for this specific
* stream. A new stream-id should only be created for a stream if the upstream
* stream is split into (potentially) multiple new streams, e.g. in a demuxer,
* but not for every single element in the pipeline.
* gst_pad_create_stream_id() or gst_pad_create_stream_id_printf() can be
* used to create a stream-id. There are no particular semantics for the
* stream-id, though it should be deterministic (to support stream matching)
* and it might be used to order streams (besides any information conveyed by
* stream flags).
*
* Returns: (transfer full): the new STREAM_START event.
*/
GstEvent *
gst_event_new_stream_start (const gchar * stream_id)
{
GstStructure *s;
g_return_val_if_fail (stream_id != NULL, NULL);
s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_START),
GST_QUARK (STREAM_ID), G_TYPE_STRING, stream_id,
GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, GST_STREAM_FLAG_NONE, NULL);
return gst_event_new_custom (GST_EVENT_STREAM_START, s);
}
/**
* gst_event_parse_stream_start:
* @event: a stream-start event.
* @stream_id: (out) (transfer none): pointer to store the stream-id
*
* Parse a stream-id @event and store the result in the given @stream_id
* location. The string stored in @stream_id must not be modified and will
* remain valid only until @event gets freed. Make a copy if you want to
* modify it or store it for later use.
*/
void
gst_event_parse_stream_start (GstEvent * event, const gchar ** stream_id)
{
const GstStructure *structure;
const GValue *val;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
structure = gst_event_get_structure (event);
val = gst_structure_id_get_value (structure, GST_QUARK (STREAM_ID));
if (stream_id)
*stream_id = g_value_get_string (val);
}
/**
* gst_event_set_stream:
* @event: a stream-start event
* @stream: (transfer none): the stream object to set
*
* Set the @stream on the stream-start @event
*
* Since: 1.10
*/
void
gst_event_set_stream (GstEvent * event, GstStream * stream)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
g_return_if_fail (gst_event_is_writable (event));
gst_structure_id_set (GST_EVENT_STRUCTURE (event),
GST_QUARK (STREAM), GST_TYPE_STREAM, stream, NULL);
}
/**
* gst_event_parse_stream:
* @event: a stream-start event
* @stream: (out) (transfer full): adress of variable to store the stream
*
* Parse a stream-start @event and extract the #GstStream from it.
*
* Since: 1.10
*/
void
gst_event_parse_stream (GstEvent * event, GstStream ** stream)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
if (stream) {
gst_structure_id_get (GST_EVENT_STRUCTURE (event),
GST_QUARK (STREAM), GST_TYPE_STREAM, stream, NULL);
}
}
/**
* gst_event_set_stream_flags:
* @event: a stream-start event
* @flags: the stream flags to set
*
* Since: 1.2
*/
void
gst_event_set_stream_flags (GstEvent * event, GstStreamFlags flags)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
g_return_if_fail (gst_event_is_writable (event));
gst_structure_id_set (GST_EVENT_STRUCTURE (event),
GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
}
/**
* gst_event_parse_stream_flags:
* @event: a stream-start event
* @flags: (out): address of variable where to store the stream flags
*
* Since: 1.2
*/
void
gst_event_parse_stream_flags (GstEvent * event, GstStreamFlags * flags)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
if (flags) {
gst_structure_id_get (GST_EVENT_STRUCTURE (event),
GST_QUARK (FLAGS), GST_TYPE_STREAM_FLAGS, flags, NULL);
}
}
/**
* gst_event_set_group_id:
* @event: a stream-start event
* @group_id: the group id to set
*
* All streams that have the same group id are supposed to be played
* together, i.e. all streams inside a container file should have the
* same group id but different stream ids. The group id should change
* each time the stream is started, resulting in different group ids
* each time a file is played for example.
*
* Use gst_util_group_id_next() to get a new group id.
*
* Since: 1.2
*/
void
gst_event_set_group_id (GstEvent * event, guint group_id)
{
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START);
g_return_if_fail (gst_event_is_writable (event));
gst_structure_id_set (GST_EVENT_STRUCTURE (event),
GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
}
/**
* gst_event_parse_group_id:
* @event: a stream-start event
* @group_id: (out): address of variable where to store the group id
*
* Returns: %TRUE if a group id was set on the event and could be parsed,
* %FALSE otherwise.
*
* Since: 1.2
*/
gboolean
gst_event_parse_group_id (GstEvent * event, guint * group_id)
{
g_return_val_if_fail (event != NULL, FALSE);
g_return_val_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_START,
FALSE);
if (group_id) {
return gst_structure_id_get (GST_EVENT_STRUCTURE (event),
GST_QUARK (GROUP_ID), G_TYPE_UINT, group_id, NULL);
}
return TRUE;
}
/**
* gst_event_new_stream_collection:
* @collection: Active collection for this data flow
*
* Create a new STREAM_COLLECTION event. The stream collection event can only
* travel downstream synchronized with the buffer flow.
*
* Source elements, demuxers and other elements that manage collections
* of streams and post #GstStreamCollection messages on the bus also send
* this event downstream on each pad involved in the collection, so that
* activation of a new collection can be tracked through the downstream
* data flow.
*
* Returns: (transfer full): the new STREAM_COLLECTION event.
*
* Since: 1.10
*/
GstEvent *
gst_event_new_stream_collection (GstStreamCollection * collection)
{
GstStructure *s;
g_return_val_if_fail (collection != NULL, NULL);
g_return_val_if_fail (GST_IS_STREAM_COLLECTION (collection), NULL);
s = gst_structure_new_id (GST_QUARK (EVENT_STREAM_COLLECTION),
GST_QUARK (COLLECTION), GST_TYPE_STREAM_COLLECTION, collection, NULL);
return gst_event_new_custom (GST_EVENT_STREAM_COLLECTION, s);
}
/**
* gst_event_parse_stream_collection:
* @event: a stream-collection event
* @collection: (out): pointer to store the collection
*
* Retrieve new #GstStreamCollection from STREAM_COLLECTION event @event.
*
* Since: 1.10
*/
void
gst_event_parse_stream_collection (GstEvent * event,
GstStreamCollection ** collection)
{
const GstStructure *structure;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_STREAM_COLLECTION);
structure = gst_event_get_structure (event);
if (collection) {
gst_structure_id_get (structure,
GST_QUARK (COLLECTION), GST_TYPE_STREAM_COLLECTION, collection, NULL);
}
}
/**
* gst_event_new_toc:
* @toc: (transfer none): #GstToc structure.
* @updated: whether @toc was updated or not.
*
* Generate a TOC event from the given @toc. The purpose of the TOC event is to
* inform elements that some kind of the TOC was found.
*
* Returns: (transfer full): a new #GstEvent.
*/
GstEvent *
gst_event_new_toc (GstToc * toc, gboolean updated)
{
GstStructure *toc_struct;
GQuark id;
g_return_val_if_fail (toc != NULL, NULL);
GST_CAT_INFO (GST_CAT_EVENT, "creating toc event");
/* need different structure names so sticky_multi event stuff on pads
* works, i.e. both TOC events are kept around */
if (gst_toc_get_scope (toc) == GST_TOC_SCOPE_GLOBAL)
id = GST_QUARK (EVENT_TOC_GLOBAL);
else
id = GST_QUARK (EVENT_TOC_CURRENT);
toc_struct = gst_structure_new_id (id,
GST_QUARK (TOC), GST_TYPE_TOC, toc,
GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
return gst_event_new_custom (GST_EVENT_TOC, toc_struct);
}
/**
* gst_event_parse_toc:
* @event: a TOC event.
* @toc: (out) (transfer full): pointer to #GstToc structure.
* @updated: (out): pointer to store TOC updated flag.
*
* Parse a TOC @event and store the results in the given @toc and @updated locations.
*/
void
gst_event_parse_toc (GstEvent * event, GstToc ** toc, gboolean * updated)
{
const GstStructure *structure;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC);
g_return_if_fail (toc != NULL);
structure = gst_event_get_structure (event);
gst_structure_id_get (structure,
GST_QUARK (TOC), GST_TYPE_TOC, toc,
GST_QUARK (UPDATED), G_TYPE_BOOLEAN, updated, NULL);
}
/**
* gst_event_new_toc_select:
* @uid: UID in the TOC to start playback from.
*
* Generate a TOC select event with the given @uid. The purpose of the
* TOC select event is to start playback based on the TOC's entry with the
* given @uid.
*
* Returns: a new #GstEvent.
*/
GstEvent *
gst_event_new_toc_select (const gchar * uid)
{
GstStructure *structure;
g_return_val_if_fail (uid != NULL, NULL);
GST_CAT_INFO (GST_CAT_EVENT, "creating toc select event for UID: %s", uid);
structure = gst_structure_new_id (GST_QUARK (EVENT_TOC_SELECT),
GST_QUARK (UID), G_TYPE_STRING, uid, NULL);
return gst_event_new_custom (GST_EVENT_TOC_SELECT, structure);
}
/**
* gst_event_parse_toc_select:
* @event: a TOC select event.
* @uid: (out) (transfer full) (allow-none): storage for the selection UID.
*
* Parse a TOC select @event and store the results in the given @uid location.
*/
void
gst_event_parse_toc_select (GstEvent * event, gchar ** uid)
{
const GstStructure *structure;
const GValue *val;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_TOC_SELECT);
structure = gst_event_get_structure (event);
val = gst_structure_id_get_value (structure, GST_QUARK (UID));
if (uid != NULL)
*uid = g_strdup (g_value_get_string (val));
}
/**
* gst_event_new_protection:
* @system_id: (transfer none): a string holding a UUID that uniquely
* identifies a protection system.
* @data: (transfer none): a #GstBuffer holding protection system specific
* information. The reference count of the buffer will be incremented by one.
* @origin: a string indicating where the protection
* information carried in the event was extracted from. The allowed values
* of this string will depend upon the protection scheme.
*
* Creates a new event containing information specific to a particular
* protection system (uniquely identified by @system_id), by which that
* protection system can acquire key(s) to decrypt a protected stream.
*
* In order for a decryption element to decrypt media
* protected using a specific system, it first needs all the
* protection system specific information necessary to acquire the decryption
* key(s) for that stream. The functions defined here enable this information
* to be passed in events from elements that extract it
* (e.g., ISOBMFF demuxers, MPEG DASH demuxers) to protection decrypter
* elements that use it.
*
* Events containing protection system specific information are created using
* #gst_event_new_protection, and they can be parsed by downstream elements
* using #gst_event_parse_protection.
*
* In Common Encryption, protection system specific information may be located
* within ISOBMFF files, both in movie (moov) boxes and movie fragment (moof)
* boxes; it may also be contained in ContentProtection elements within MPEG
* DASH MPDs. The events created by #gst_event_new_protection contain data
* identifying from which of these locations the encapsulated protection system
* specific information originated. This origin information is required as
* some protection systems use different encodings depending upon where the
* information originates.
*
* The events returned by gst_event_new_protection() are implemented
* in such a way as to ensure that the most recently-pushed protection info
* event of a particular @origin and @system_id will
* be stuck to the output pad of the sending element.
*
* Returns: a #GST_EVENT_PROTECTION event, if successful; %NULL
* if unsuccessful.
*
* Since: 1.6
*/
GstEvent *
gst_event_new_protection (const gchar * system_id,
GstBuffer * data, const gchar * origin)
{
gchar *event_name;
GstEvent *event;
GstStructure *s;
g_return_val_if_fail (system_id != NULL, NULL);
g_return_val_if_fail (data != NULL, NULL);
event_name =
g_strconcat ("GstProtectionEvent", origin ? "-" : "",
origin ? origin : "", "-", system_id, NULL);
GST_CAT_INFO (GST_CAT_EVENT, "creating protection event %s", event_name);
s = gst_structure_new (event_name, "data", GST_TYPE_BUFFER, data,
"system_id", G_TYPE_STRING, system_id, NULL);
if (origin)
gst_structure_set (s, "origin", G_TYPE_STRING, origin, NULL);
event = gst_event_new_custom (GST_EVENT_PROTECTION, s);
g_free (event_name);
return event;
}
/**
* gst_event_parse_protection:
* @event: a #GST_EVENT_PROTECTION event.
* @system_id: (out) (allow-none) (transfer none): pointer to store the UUID
* string uniquely identifying a content protection system.
* @data: (out) (allow-none) (transfer none): pointer to store a #GstBuffer
* holding protection system specific information.
* @origin: (out) (allow-none) (transfer none): pointer to store a value that
* indicates where the protection information carried by @event was extracted
* from.
*
* Parses an event containing protection system specific information and stores
* the results in @system_id, @data and @origin. The data stored in @system_id,
* @origin and @data are valid until @event is released.
*
* Since: 1.6
*/
void
gst_event_parse_protection (GstEvent * event, const gchar ** system_id,
GstBuffer ** data, const gchar ** origin)
{
const GstStructure *s;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_IS_EVENT (event));
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_PROTECTION);
s = gst_event_get_structure (event);
if (origin)
*origin = gst_structure_get_string (s, "origin");
if (system_id)
*system_id = gst_structure_get_string (s, "system_id");
if (data) {
const GValue *value = gst_structure_get_value (s, "data");
*data = gst_value_get_buffer (value);
}
}
/**
* gst_event_new_segment_done:
* @format: The format of the position being done
* @position: The position of the segment being done
*
* Create a new segment-done event. This event is sent by elements that
* finish playback of a segment as a result of a segment seek.
*
* Returns: (transfer full): a new #GstEvent
*/
GstEvent *
gst_event_new_segment_done (GstFormat format, gint64 position)
{
GstEvent *event;
GstStructure *structure;
GST_CAT_INFO (GST_CAT_EVENT, "creating segment-done event");
structure = gst_structure_new_id (GST_QUARK (EVENT_SEGMENT_DONE),
GST_QUARK (FORMAT), GST_TYPE_FORMAT, format,
GST_QUARK (POSITION), G_TYPE_INT64, position, NULL);
event = gst_event_new_custom (GST_EVENT_SEGMENT_DONE, structure);
return event;
}
/**
* gst_event_parse_segment_done:
* @event: A valid #GstEvent of type GST_EVENT_SEGMENT_DONE.
* @format: (out) (allow-none): Result location for the format, or %NULL
* @position: (out) (allow-none): Result location for the position, or %NULL
*
* Extracts the position and format from the segment done message.
*
*/
void
gst_event_parse_segment_done (GstEvent * event, GstFormat * format,
gint64 * position)
{
const GstStructure *structure;
const GValue *val;
g_return_if_fail (event != NULL);
g_return_if_fail (GST_EVENT_TYPE (event) == GST_EVENT_SEGMENT_DONE);
structure = gst_event_get_structure (event);
val = gst_structure_id_get_value (structure, GST_QUARK (FORMAT));
if (format != NULL)
*format = g_value_get_enum (val);
val = gst_structure_id_get_value (structure, GST_QUARK (POSITION));
if (position != NULL)
*position = g_value_get_int64 (val);
}