gstreamer/gst/gstevent.h
Tim-Philipp Müller 2a1af2c947 gst/gstevent.h: Clarify docs for GST_SEEK_TYPE_CUR (#534505).
Original commit message from CVS:
* gst/gstevent.h:
Clarify docs for GST_SEEK_TYPE_CUR (#534505).
2008-05-25 14:44:44 +00:00

435 lines
15 KiB
C

/* 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.h: Header for 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.
*/
#ifndef __GST_EVENT_H__
#define __GST_EVENT_H__
#include <gst/gstminiobject.h>
#include <gst/gstformat.h>
#include <gst/gstobject.h>
#include <gst/gstclock.h>
#include <gst/gststructure.h>
#include <gst/gsttaglist.h>
G_BEGIN_DECLS
/**
* GstEventTypeFlags:
* @GST_EVENT_TYPE_UPSTREAM: Set if the event can travel upstream.
* @GST_EVENT_TYPE_DOWNSTREAM: Set if the event can travel downstream.
* @GST_EVENT_TYPE_SERIALIZED: Set if the event should be serialized with data
* flow.
*
* #GstEventTypeFlags indicate the aspects of the different #GstEventType
* values. You can get the type flags of a #GstEventType with the
* gst_event_type_get_flags() function.
*/
typedef enum {
GST_EVENT_TYPE_UPSTREAM = 1 << 0,
GST_EVENT_TYPE_DOWNSTREAM = 1 << 1,
GST_EVENT_TYPE_SERIALIZED = 1 << 2
} GstEventTypeFlags;
/**
* GST_EVENT_TYPE_BOTH:
*
* The same thing as #GST_EVENT_TYPE_UPSTREAM | #GST_EVENT_TYPE_DOWNSTREAM.
*/
#define GST_EVENT_TYPE_BOTH \
(GST_EVENT_TYPE_UPSTREAM | GST_EVENT_TYPE_DOWNSTREAM)
#define GST_EVENT_TYPE_SHIFT 4
/**
* GST_EVENT_MAKE_TYPE:
* @num: the event number to create
* @flags: the event flags
*
* when making custom event types, use this macro with the num and
* the given flags
*/
#define GST_EVENT_MAKE_TYPE(num,flags) \
(((num) << GST_EVENT_TYPE_SHIFT) | (flags))
#define FLAG(name) GST_EVENT_TYPE_##name
/**
* GstEventType:
* @GST_EVENT_UNKNOWN: unknown event.
* @GST_EVENT_FLUSH_START: Start a flush operation
* @GST_EVENT_FLUSH_STOP: Stop a flush operation
* @GST_EVENT_EOS: End-Of-Stream. No more data is to be expected to follow
* without a NEWSEGMENT event.
* @GST_EVENT_NEWSEGMENT: A new media segment follows in the dataflow.
* @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
* @GST_EVENT_BUFFERSIZE: Notification of buffering requirements
* @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
* that the downstream elements are being starved of or
* flooded with data.
* @GST_EVENT_SEEK: A request for a new playback position and rate.
* @GST_EVENT_NAVIGATION: Navigation events are usually used for communicating
* user requests, such as mouse or keyboard movements,
* to upstream elements.
* @GST_EVENT_LATENCY: Notification of new latency adjustment. Since: 0.10.12
* @GST_EVENT_CUSTOM_UPSTREAM: Upstream custom event
* @GST_EVENT_CUSTOM_DOWNSTREAM: Downstream custom event that travels in the
* data flow.
* @GST_EVENT_CUSTOM_DOWNSTREAM_OOB: Custom out-of-band downstream event.
* @GST_EVENT_CUSTOM_BOTH: Custom upstream or downstream event.
* In-band when travelling downstream.
* @GST_EVENT_CUSTOM_BOTH_OOB: Custom upstream or downstream out-of-band event.
*
* #GstEventType lists the standard event types that can be sent in a pipeline.
*
* The custom event types can be used for private messages between elements
* that can't be expressed using normal
* GStreamer buffer passing semantics. Custom events carry an arbitrary
* #GstStructure.
* Specific custom events are distinguished by the name of the structure.
*/
/* NOTE: keep in sync with quark registration in gstevent.c */
typedef enum {
GST_EVENT_UNKNOWN = GST_EVENT_MAKE_TYPE (0, 0),
/* bidirectional events */
GST_EVENT_FLUSH_START = GST_EVENT_MAKE_TYPE (1, FLAG(BOTH)),
GST_EVENT_FLUSH_STOP = GST_EVENT_MAKE_TYPE (2, FLAG(BOTH) | FLAG(SERIALIZED)),
/* downstream serialized events */
GST_EVENT_EOS = GST_EVENT_MAKE_TYPE (5, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
GST_EVENT_NEWSEGMENT = GST_EVENT_MAKE_TYPE (6, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
GST_EVENT_TAG = GST_EVENT_MAKE_TYPE (7, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
GST_EVENT_BUFFERSIZE = GST_EVENT_MAKE_TYPE (8, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
/* upstream events */
GST_EVENT_QOS = GST_EVENT_MAKE_TYPE (15, FLAG(UPSTREAM)),
GST_EVENT_SEEK = GST_EVENT_MAKE_TYPE (16, FLAG(UPSTREAM)),
GST_EVENT_NAVIGATION = GST_EVENT_MAKE_TYPE (17, FLAG(UPSTREAM)),
GST_EVENT_LATENCY = GST_EVENT_MAKE_TYPE (18, FLAG(UPSTREAM)),
/* custom events start here */
GST_EVENT_CUSTOM_UPSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(UPSTREAM)),
GST_EVENT_CUSTOM_DOWNSTREAM = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
GST_EVENT_CUSTOM_DOWNSTREAM_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(DOWNSTREAM)),
GST_EVENT_CUSTOM_BOTH = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH) | FLAG(SERIALIZED)),
GST_EVENT_CUSTOM_BOTH_OOB = GST_EVENT_MAKE_TYPE (32, FLAG(BOTH))
} GstEventType;
#undef FLAG
/**
* GST_EVENT_TRACE_NAME:
*
* The name used for memory allocation tracing
*/
#define GST_EVENT_TRACE_NAME "GstEvent"
typedef struct _GstEvent GstEvent;
typedef struct _GstEventClass GstEventClass;
#define GST_TYPE_EVENT (gst_event_get_type())
#define GST_IS_EVENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_EVENT))
#define GST_IS_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_EVENT))
#define GST_EVENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_EVENT, GstEventClass))
#define GST_EVENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_EVENT, GstEvent))
#define GST_EVENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_EVENT, GstEventClass))
#define GST_EVENT_CAST(obj) ((GstEvent *)(obj))
/**
* GST_EVENT_TYPE:
* @event: the event to query
*
* Get the #GstEventType of the event.
*/
#define GST_EVENT_TYPE(event) (GST_EVENT_CAST(event)->type)
/**
* GST_EVENT_TYPE_NAME:
* @event: the event to query
*
* Get a constant string representation of the #GstEventType of the event.
*/
#define GST_EVENT_TYPE_NAME(event) (gst_event_type_get_name(GST_EVENT_TYPE(event)))
/**
* GST_EVENT_TIMESTAMP:
* @event: the event to query
*
* Get the #GstClockTime timestamp of the event. This is the time when the event
* was created.
*/
#define GST_EVENT_TIMESTAMP(event) (GST_EVENT_CAST(event)->timestamp)
/**
* GST_EVENT_SRC:
* @event: the event to query
*
* The source #GstObject that generated this event.
*/
#define GST_EVENT_SRC(event) (GST_EVENT_CAST(event)->src)
/**
* GST_EVENT_IS_UPSTREAM:
* @ev: the event to query
*
* Check if an event can travel upstream.
*/
#define GST_EVENT_IS_UPSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_UPSTREAM)
/**
* GST_EVENT_IS_DOWNSTREAM:
* @ev: the event to query
*
* Check if an event can travel downstream.
*/
#define GST_EVENT_IS_DOWNSTREAM(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_DOWNSTREAM)
/**
* GST_EVENT_IS_SERIALIZED:
* @ev: the event to query
*
* Check if an event is serialized with the data stream.
*/
#define GST_EVENT_IS_SERIALIZED(ev) !!(GST_EVENT_TYPE (ev) & GST_EVENT_TYPE_SERIALIZED)
/**
* gst_event_replace:
* @old_event: pointer to a pointer to a #GstEvent to be replaced.
* @new_event: pointer to a #GstEvent that will replace the event pointed to
* by @old_event.
*
* Modifies a pointer to a #GstEvent to point to a different #GstEvent. The
* modification is done atomically (so this is useful for ensuring thread safety
* in some cases), and the reference counts are updated appropriately (the old
* event is unreffed, the new one is reffed).
*
* Either @new_event or the #GstEvent pointed to by @old_event may be NULL.
*
* Since: 0.10.3
*/
#define gst_event_replace(old_event,new_event) \
gst_mini_object_replace ((GstMiniObject **)(old_event), GST_MINI_OBJECT (new_event))
/**
* GstSeekType:
* @GST_SEEK_TYPE_NONE: no change in position is required
* @GST_SEEK_TYPE_CUR: change relative to currently configured segment. This
* can't be used to seek relative to the current playback position - do a
* position query, calculate the desired position and then do an absolute
* position seek instead if that's what you want to do.
* @GST_SEEK_TYPE_SET: absolute position is requested
* @GST_SEEK_TYPE_END: relative position to duration is requested
*
* The different types of seek events. When constructing a seek event with
* gst_event_new_seek(), a format, a seek method and optional flags are to
* be provided. The seek event is then inserted into the graph with
* gst_pad_send_event() or gst_element_send_event().
*/
typedef enum {
/* one of these */
GST_SEEK_TYPE_NONE = 0,
GST_SEEK_TYPE_CUR = 1,
GST_SEEK_TYPE_SET = 2,
GST_SEEK_TYPE_END = 3
} GstSeekType;
/**
* GstSeekFlags:
* @GST_SEEK_FLAG_NONE: no flag
* @GST_SEEK_FLAG_FLUSH: flush pipeline
* @GST_SEEK_FLAG_ACCURATE: accurate position is requested, this might
* be considerably slower for some formats.
* @GST_SEEK_FLAG_KEY_UNIT: seek to the nearest keyframe. This might be
* faster but less accurate.
* @GST_SEEK_FLAG_SEGMENT: perform a segment seek.
*
* Flags to be used with gst_element_seek() or gst_event_new_seek(). All flags
* can be used together.
*
* A non flushing seek might take some time to perform as the currently
* playing data in the pipeline will not be cleared.
*
* An accurate seek might be slower for formats that don't have any indexes
* or timestamp markers in the stream. Specifying this flag might require a
* complete scan of the file in those cases.
*
* When performing a segment seek: after the playback of the segment completes,
* no EOS will be emmited by the element that performed the seek, but a
* #GST_MESSAGE_SEGMENT_DONE message will be posted on the bus by the element.
* When this message is posted, it is possible to send a new seek event to
* continue playback. With this seek method it is possible to perform seemless
* looping or simple linear editing.
*/
typedef enum {
GST_SEEK_FLAG_NONE = 0,
GST_SEEK_FLAG_FLUSH = (1 << 0),
GST_SEEK_FLAG_ACCURATE = (1 << 1),
GST_SEEK_FLAG_KEY_UNIT = (1 << 2),
GST_SEEK_FLAG_SEGMENT = (1 << 3)
} GstSeekFlags;
/**
* GstEvent:
* @mini_object: the parent structure
* @type: the #GstEventType of the event
* @timestamp: the timestamp of the event
* @src: the src of the event
* @structure: the #GstStructure containing the event info.
*
* A #GstEvent.
*/
struct _GstEvent {
GstMiniObject mini_object;
/*< public >*/ /* with COW */
GstEventType type;
guint64 timestamp;
GstObject *src;
GstStructure *structure;
/*< private >*/
gpointer _gst_reserved;
};
struct _GstEventClass {
GstMiniObjectClass mini_object_class;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
const gchar* gst_event_type_get_name (GstEventType type);
GQuark gst_event_type_to_quark (GstEventType type);
GstEventTypeFlags
gst_event_type_get_flags (GstEventType type);
GType gst_event_get_type (void);
/* refcounting */
/**
* gst_event_ref:
* @event: The event to refcount
*
* Increase the refcount of this event.
*
* Returns: @event (for convenience when doing assignments)
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstEvent * gst_event_ref (GstEvent * event);
#endif
static inline GstEvent *
gst_event_ref (GstEvent * ev)
{
/* not using a macro here because gcc-4.1 will complain
* if the return value isn't used (because of the cast) */
return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT (ev));
}
/**
* gst_event_unref:
* @ev: The event to refcount
*
* Decrease the refcount of an event, freeing it if the refcount reaches 0.
*/
#define gst_event_unref(ev) gst_mini_object_unref (GST_MINI_OBJECT (ev))
/* copy event */
/**
* gst_event_copy:
* @ev: The event to copy
*
* Copy the event using the event specific copy function.
*/
#define gst_event_copy(ev) GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT (ev)))
/* custom event */
GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure);
const GstStructure *
gst_event_get_structure (GstEvent *event);
gboolean gst_event_has_name (GstEvent *event, const gchar *name);
/* flush events */
GstEvent * gst_event_new_flush_start (void);
GstEvent * gst_event_new_flush_stop (void);
/* EOS event */
GstEvent * gst_event_new_eos (void);
/* newsegment events */
GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
GstFormat format,
gint64 start, gint64 stop,
gint64 position);
GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
gdouble applied_rate,
GstFormat format,
gint64 start, gint64 stop,
gint64 position);
void gst_event_parse_new_segment (GstEvent *event,
gboolean *update,
gdouble *rate,
GstFormat *format,
gint64 *start, gint64 *stop,
gint64 *position);
void gst_event_parse_new_segment_full (GstEvent *event,
gboolean *update,
gdouble *rate,
gdouble *applied_rate,
GstFormat *format,
gint64 *start, gint64 *stop,
gint64 *position);
/* tag event */
GstEvent* gst_event_new_tag (GstTagList *taglist);
void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
/* buffer */
GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
gboolean async);
void gst_event_parse_buffer_size (GstEvent *event, GstFormat *format, gint64 *minsize,
gint64 *maxsize, gboolean *async);
/* QOS events */
GstEvent* gst_event_new_qos (gdouble proportion, GstClockTimeDiff diff,
GstClockTime timestamp);
void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
GstClockTime *timestamp);
/* seek event */
GstEvent* gst_event_new_seek (gdouble rate, GstFormat format, GstSeekFlags flags,
GstSeekType start_type, gint64 start,
GstSeekType stop_type, gint64 stop);
void gst_event_parse_seek (GstEvent *event, gdouble *rate, GstFormat *format,
GstSeekFlags *flags,
GstSeekType *start_type, gint64 *start,
GstSeekType *stop_type, gint64 *stop);
/* navigation event */
GstEvent* gst_event_new_navigation (GstStructure *structure);
/* latency event */
GstEvent* gst_event_new_latency (GstClockTime latency);
void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
G_END_DECLS
#endif /* __GST_EVENT_H__ */