gstreamer/gst/gstevent.h
Vincent Penquerc'h a975fadbaf event: add new seek snap flags
They can be used to select snapping behavior (to previous, next, or
nearest location, where relevant) when seeking.

The seeking implementation (eg, demuxer) may currently ignore some
or all of these flags.
2012-04-30 09:52:04 +01:00

571 lines
24 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>
#include <gst/gsttoc.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. This event clears all data
* from the pipeline and unblock all streaming threads.
* @GST_EVENT_FLUSH_STOP: Stop a flush operation. This event resets the
* running-time of the pipeline.
* @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. The
* segment events contains information for clipping buffers and
* converting buffer timestamps to running-time and
* stream-time.
* @GST_EVENT_TAG: A new set of metadata tags has been found in the stream.
* @GST_EVENT_BUFFERSIZE: Notification of buffering requirements. Currently not
* used yet.
* @GST_EVENT_SINK_MESSAGE: An event that sinks turn into a message. Used to
* send messages that should be emitted in sync with
* rendering.
* Since: 0.10.26
* @GST_EVENT_TOC: An event which indicates that a new table of contents (TOC)
was found or updated. Since: 0.10.37
* @GST_EVENT_QOS: A quality message. Used to indicate to upstream elements
* that the downstream elements should adjust their processing
* rate.
* @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. Sinks will use
* the latency information to adjust their synchronisation.
* Since: 0.10.12
* @GST_EVENT_STEP: A request for stepping through the media. Sinks will usually
* execute the step operation. Since: 0.10.24
* @GST_EVENT_TOC_SELECT: A request for a new playback position based on TOC
* entry's UID. Since 0.10.37
* @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)),
GST_EVENT_SINK_MESSAGE = GST_EVENT_MAKE_TYPE (9, FLAG(DOWNSTREAM) | FLAG(SERIALIZED)),
GST_EVENT_TOC = GST_EVENT_MAKE_TYPE (10, 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)),
GST_EVENT_STEP = GST_EVENT_MAKE_TYPE (19, FLAG(UPSTREAM)),
GST_EVENT_TOC_SELECT = GST_EVENT_MAKE_TYPE (20, 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: (inout) (transfer full): pointer to a pointer to a #GstEvent
* to be replaced.
* @new_event: (allow-none) (transfer none): 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
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC void gst_event_replace (GstEvent **old_event, GstEvent *new_event);
#endif
static inline void
gst_event_replace (GstEvent **old_event, GstEvent *new_event)
{
gst_mini_object_replace ((GstMiniObject **) old_event, (GstMiniObject *) 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.
* @GST_SEEK_FLAG_SKIP: when doing fast foward or fast reverse playback, allow
* elements to skip frames instead of generating all
* frames. Since 0.10.22.
* @GST_SEEK_FLAG_SNAP_BEFORE: go to a location before the requested position,
* if KEY_UNIT this means the keyframe at or before the
* requested position the one at or before the seek target.
* Since 0.10.37.
* @GST_SEEK_FLAG_SNAP_AFTER: go to a location after the requested position,
* if KEY_UNIT this means the keyframe at of after the
* requested position. Since 0.10.37.
* @GST_SEEK_FLAG_SNAP_NEAREST: go to a position near the requested position,
* if KEY_UNIT this means the keyframe closest to the
* requested position, if both keyframes are at an equal
* distance, behaves like SNAP_BEFORE. Since 0.10.37.
*
* 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 seamless
* looping or simple linear editing.
*
* When doing fast forward (rate > 1.0) or fast reverse (rate < -1.0) trickmode
* playback, the @GST_SEEK_FLAG_SKIP flag can be used to instruct decoders
* and demuxers to adjust the playback rate by skipping frames. This can improve
* performance and decrease CPU usage because not all frames need to be decoded.
*
* The @GST_SEEK_FLAG_SNAP_BEFORE flag can be used to snap to the previous
* relevant location, and the @GST_SEEK_FLAG_SNAP_AFTER flag can be used to
* select the next relevant location. If KEY_UNIT is specified, the relevant
* location is a keyframe. If both flags are specified, the nearest of these
* locations will be selected. If none are specified, the implementation is
* free to select whichever it wants.
* The before and after here are in running time, so when playing backwards,
* the next location refers to the one that will played in next, and not the
* one that is located after in the actual source stream.
*
* Also see part-seeking.txt in the GStreamer design documentation for more
* details on the meaning of these flags and the behaviour expected of
* elements that handle them.
*/
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),
GST_SEEK_FLAG_SKIP = (1 << 4),
GST_SEEK_FLAG_SNAP_BEFORE = (1 << 5),
GST_SEEK_FLAG_SNAP_AFTER = (1 << 6),
GST_SEEK_FLAG_SNAP_NEAREST = GST_SEEK_FLAG_SNAP_BEFORE | GST_SEEK_FLAG_SNAP_AFTER,
/* Careful to restart next flag with 1<<7 here */
} GstSeekFlags;
/**
* GstQOSType:
* @GST_QOS_TYPE_OVERFLOW: The QoS event type that is produced when downstream
* elements are producing data too quickly and the element can't keep up
* processing the data. Upstream should reduce their processing rate. This
* type is also used when buffers arrive early or in time.
* @GST_QOS_TYPE_UNDERFLOW: The QoS event type that is produced when downstream
* elements are producing data too slowly and need to speed up their processing
* rate.
* @GST_QOS_TYPE_THROTTLE: The QoS event type that is produced when the
* application enabled throttling to limit the datarate.
*
* The different types of QoS events that can be given to the
* gst_event_new_qos_full() method.
*
* Since: 0.10.33
*/
typedef enum {
GST_QOS_TYPE_OVERFLOW = 0,
GST_QOS_TYPE_UNDERFLOW = 1,
GST_QOS_TYPE_THROTTLE = 2
} GstQOSType;
/**
* 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 >*/
union {
guint32 seqnum;
gpointer _gst_reserved;
} abidata;
};
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: (transfer full): @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 * event)
{
return (GstEvent *) gst_mini_object_ref (GST_MINI_OBJECT_CAST (event));
}
/**
* gst_event_unref:
* @event: (transfer full): the event to refcount
*
* Decrease the refcount of an event, freeing it if the refcount reaches 0.
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC void gst_event_unref (GstEvent * event);
#endif
static inline void
gst_event_unref (GstEvent * event)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (event));
}
/* copy event */
/**
* gst_event_copy:
* @event: The event to copy
*
* Copy the event using the event specific copy function.
*
* Returns: (transfer full): the new event
*/
#ifdef _FOOL_GTK_DOC_
G_INLINE_FUNC GstEvent * gst_event_copy (const GstEvent * event);
#endif
static inline GstEvent *
gst_event_copy (const GstEvent * event)
{
return GST_EVENT_CAST (gst_mini_object_copy (GST_MINI_OBJECT_CONST_CAST (event)));
}
/* custom event */
GstEvent* gst_event_new_custom (GstEventType type, GstStructure *structure) G_GNUC_MALLOC;
const GstStructure *
gst_event_get_structure (GstEvent *event);
gboolean gst_event_has_name (GstEvent *event, const gchar *name);
/* identifiers for events and messages */
guint32 gst_event_get_seqnum (GstEvent *event);
void gst_event_set_seqnum (GstEvent *event, guint32 seqnum);
/* flush events */
GstEvent * gst_event_new_flush_start (void) G_GNUC_MALLOC;
GstEvent * gst_event_new_flush_stop (void) G_GNUC_MALLOC;
/* EOS event */
GstEvent * gst_event_new_eos (void) G_GNUC_MALLOC;
/* newsegment events */
GstEvent* gst_event_new_new_segment (gboolean update, gdouble rate,
GstFormat format,
gint64 start, gint64 stop,
gint64 position) G_GNUC_MALLOC;
GstEvent* gst_event_new_new_segment_full (gboolean update, gdouble rate,
gdouble applied_rate,
GstFormat format,
gint64 start, gint64 stop,
gint64 position) G_GNUC_MALLOC;
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) G_GNUC_MALLOC;
void gst_event_parse_tag (GstEvent *event, GstTagList **taglist);
/* TOC event */
GstEvent* gst_event_new_toc (GstToc *toc, gboolean updated);
void gst_event_parse_toc (GstEvent *event, GstToc **toc, gboolean *updated);
/* buffer */
GstEvent * gst_event_new_buffer_size (GstFormat format, gint64 minsize, gint64 maxsize,
gboolean async) G_GNUC_MALLOC;
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) G_GNUC_MALLOC;
GstEvent* gst_event_new_qos_full (GstQOSType type, gdouble proportion,
GstClockTimeDiff diff, GstClockTime timestamp) G_GNUC_MALLOC;
void gst_event_parse_qos (GstEvent *event, gdouble *proportion, GstClockTimeDiff *diff,
GstClockTime *timestamp);
void gst_event_parse_qos_full (GstEvent *event, GstQOSType *type,
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) G_GNUC_MALLOC;
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) G_GNUC_MALLOC;
/* latency event */
GstEvent* gst_event_new_latency (GstClockTime latency) G_GNUC_MALLOC;
void gst_event_parse_latency (GstEvent *event, GstClockTime *latency);
/* step event */
GstEvent* gst_event_new_step (GstFormat format, guint64 amount, gdouble rate,
gboolean flush, gboolean intermediate) G_GNUC_MALLOC;
void gst_event_parse_step (GstEvent *event, GstFormat *format, guint64 *amount,
gdouble *rate, gboolean *flush, gboolean *intermediate);
/* TOC select event */
GstEvent* gst_event_new_toc_select (const gchar *uid);
void gst_event_parse_toc_select (GstEvent *event, gchar **uid);
G_END_DECLS
#endif /* __GST_EVENT_H__ */