mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-11-15 22:01:27 +00:00
Code Issues 1 Projects Releases Wiki Activity
gstreamer/gst/gstelement.h
Thibault Saunier b15d59b53c doc: Fix some doctsing making GI happy
2017-04-21 10:51:59 -03:00

916 lines
42 KiB
C
Raw Blame History

/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000,2004 Wim Taymans <wim@fluendo.com>
*
* gstelement.h: Header for GstElement
*
* 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.
*/
#ifndef __GST_ELEMENT_H__
#define __GST_ELEMENT_H__
#include <glib.h>
G_BEGIN_DECLS
/* gstelement.h and gstelementfactory.h include eachother */
typedef struct _GstElement GstElement;
typedef struct _GstElementClass GstElementClass;
/* gstmessage.h needs State */
/**
* GstState:
* @GST_STATE_VOID_PENDING: no pending state.
* @GST_STATE_NULL : the NULL state or initial state of an element.
* @GST_STATE_READY : the element is ready to go to PAUSED.
* @GST_STATE_PAUSED : the element is PAUSED, it is ready to accept and
* process data. Sink elements however only accept one
* buffer and then block.
* @GST_STATE_PLAYING : the element is PLAYING, the #GstClock is running and
* the data is flowing.
*
* The possible states an element can be in. States can be changed using
* gst_element_set_state() and checked using gst_element_get_state().
*/
typedef enum {
GST_STATE_VOID_PENDING = 0,
GST_STATE_NULL = 1,
GST_STATE_READY = 2,
GST_STATE_PAUSED = 3,
GST_STATE_PLAYING = 4
} GstState;
#define GST_TYPE_ELEMENT (gst_element_get_type ())
#define GST_IS_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT))
#define GST_IS_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT))
#define GST_ELEMENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ELEMENT, GstElementClass))
#define GST_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement))
#define GST_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass))
#define GST_ELEMENT_CAST(obj) ((GstElement*)(obj))
/**
* GstStateChangeReturn:
* @GST_STATE_CHANGE_FAILURE : the state change failed
* @GST_STATE_CHANGE_SUCCESS : the state change succeeded
* @GST_STATE_CHANGE_ASYNC : the state change will happen asynchronously
* @GST_STATE_CHANGE_NO_PREROLL: the state change succeeded but the element
* cannot produce data in %GST_STATE_PAUSED.
* This typically happens with live sources.
*
* The possible return values from a state change function such as
* gst_element_set_state(). Only @GST_STATE_CHANGE_FAILURE is a real failure.
*/
typedef enum {
GST_STATE_CHANGE_FAILURE = 0,
GST_STATE_CHANGE_SUCCESS = 1,
GST_STATE_CHANGE_ASYNC = 2,
GST_STATE_CHANGE_NO_PREROLL = 3
} GstStateChangeReturn;
#include <gst/gstconfig.h>
#include <gst/gstobject.h>
#include <gst/gstpad.h>
#include <gst/gstbus.h>
#include <gst/gstclock.h>
#include <gst/gstelementfactory.h>
#include <gst/gstplugin.h>
#include <gst/gstpluginfeature.h>
#include <gst/gstiterator.h>
#include <gst/gstmessage.h>
#include <gst/gstquery.h>
#include <gst/gsttaglist.h>
#include <gst/gstcontext.h>
/* NOTE: this probably should be done with an #ifdef to decide
* whether to safe-cast or to just do the non-checking cast.
*/
/**
* GST_STATE:
* @elem: a #GstElement to return state for.
*
* This macro returns the current #GstState of the element.
*/
#define GST_STATE(elem) (GST_ELEMENT_CAST(elem)->current_state)
/**
* GST_STATE_NEXT:
* @elem: a #GstElement to return the next state for.
*
* This macro returns the next #GstState of the element.
*/
#define GST_STATE_NEXT(elem) (GST_ELEMENT_CAST(elem)->next_state)
/**
* GST_STATE_PENDING:
* @elem: a #GstElement to return the pending state for.
*
* This macro returns the currently pending #GstState of the element.
*/
#define GST_STATE_PENDING(elem) (GST_ELEMENT_CAST(elem)->pending_state)
/**
* GST_STATE_TARGET:
* @elem: a #GstElement to return the target state for.
*
* This macro returns the target #GstState of the element.
*/
#define GST_STATE_TARGET(elem) (GST_ELEMENT_CAST(elem)->target_state)
/**
* GST_STATE_RETURN:
* @elem: a #GstElement to return the last state result for.
*
* This macro returns the last #GstStateChangeReturn value.
*/
#define GST_STATE_RETURN(elem) (GST_ELEMENT_CAST(elem)->last_return)
#define __GST_SIGN(val) ((val) < 0 ? -1 : ((val) > 0 ? 1 : 0))
/**
* GST_STATE_GET_NEXT:
* @cur: A starting #GstState
* @pending: A target #GstState
*
* Given a current state @cur and a target state @pending, calculate the next (intermediate)
* #GstState.
*/
#define GST_STATE_GET_NEXT(cur,pending) ((GstState)((cur) + __GST_SIGN ((gint)(pending) - (gint)(cur))))
/**
* GST_STATE_TRANSITION:
* @cur: A current state
* @next: A next state
*
* Given a current state @cur and a next state @next, calculate the associated
* #GstStateChange transition.
*/
#define GST_STATE_TRANSITION(cur,next) ((GstStateChange)(((cur)<<3)|(next)))
/**
* GST_STATE_TRANSITION_CURRENT:
* @trans: A #GstStateChange
*
* Given a state transition @trans, extract the current #GstState.
*/
#define GST_STATE_TRANSITION_CURRENT(trans) ((GstState)((trans)>>3))
/**
* GST_STATE_TRANSITION_NEXT:
* @trans: A #GstStateChange
*
* Given a state transition @trans, extract the next #GstState.
*/
#define GST_STATE_TRANSITION_NEXT(trans) ((GstState)((trans)&0x7))
/**
* GstStateChange:
* @GST_STATE_CHANGE_NULL_TO_READY : state change from NULL to READY.
* * The element must check if the resources it needs are available. Device
* sinks and -sources typically try to probe the device to constrain their
* caps.
* * The element opens the device (in case feature need to be probed).
* @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED.
* * The element pads are activated in order to receive data in PAUSED.
* Streaming threads are started.
* * Some elements might need to return %GST_STATE_CHANGE_ASYNC and complete
* the state change when they have enough information. It is a requirement
* for sinks to return %GST_STATE_CHANGE_ASYNC and complete the state change
* when they receive the first buffer or %GST_EVENT_EOS (preroll).
* Sinks also block the dataflow when in PAUSED.
* * A pipeline resets the running_time to 0.
* * Live sources return %GST_STATE_CHANGE_NO_PREROLL and don't generate data.
* @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING.
* * Most elements ignore this state change.
* * The pipeline selects a #GstClock and distributes this to all the children
* before setting them to PLAYING. This means that it is only allowed to
* synchronize on the #GstClock in the PLAYING state.
* * The pipeline uses the #GstClock and the running_time to calculate the
* base_time. The base_time is distributed to all children when performing
* the state change.
* * Sink elements stop blocking on the preroll buffer or event and start
* rendering the data.
* * Sinks can post %GST_MESSAGE_EOS in the PLAYING state. It is not allowed
* to post %GST_MESSAGE_EOS when not in the PLAYING state.
* * While streaming in PAUSED or PLAYING elements can create and remove
* sometimes pads.
* * Live sources start generating data and return %GST_STATE_CHANGE_SUCCESS.
* @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED.
* * Most elements ignore this state change.
* * The pipeline calculates the running_time based on the last selected
* #GstClock and the base_time. It stores this information to continue
* playback when going back to the PLAYING state.
* * Sinks unblock any #GstClock wait calls.
* * When a sink does not have a pending buffer to play, it returns
* #GST_STATE_CHANGE_ASYNC from this state change and completes the state
* change when it receives a new buffer or an %GST_EVENT_EOS.
* * Any queued %GST_MESSAGE_EOS items are removed since they will be reposted
* when going back to the PLAYING state. The EOS messages are queued in
* #GstBin containers.
* * Live sources stop generating data and return %GST_STATE_CHANGE_NO_PREROLL.
* @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY.
* * Sinks unblock any waits in the preroll.
* * Elements unblock any waits on devices
* * Chain or get_range functions return %GST_FLOW_FLUSHING.
* * The element pads are deactivated so that streaming becomes impossible and
* all streaming threads are stopped.
* * The sink forgets all negotiated formats
* * Elements remove all sometimes pads
* @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL.
* * Elements close devices
* * Elements reset any internal state.
*
* These are the different state changes an element goes through.
* %GST_STATE_NULL &rArr; %GST_STATE_PLAYING is called an upwards state change
* and %GST_STATE_PLAYING &rArr; %GST_STATE_NULL a downwards state change.
*/
typedef enum /*< flags=0 >*/
{
GST_STATE_CHANGE_NULL_TO_READY = (GST_STATE_NULL<<3) | GST_STATE_READY,
GST_STATE_CHANGE_READY_TO_PAUSED = (GST_STATE_READY<<3) | GST_STATE_PAUSED,
GST_STATE_CHANGE_PAUSED_TO_PLAYING = (GST_STATE_PAUSED<<3) | GST_STATE_PLAYING,
GST_STATE_CHANGE_PLAYING_TO_PAUSED = (GST_STATE_PLAYING<<3) | GST_STATE_PAUSED,
GST_STATE_CHANGE_PAUSED_TO_READY = (GST_STATE_PAUSED<<3) | GST_STATE_READY,
GST_STATE_CHANGE_READY_TO_NULL = (GST_STATE_READY<<3) | GST_STATE_NULL
} GstStateChange;
/**
* GstElementFlags:
* @GST_ELEMENT_FLAG_LOCKED_STATE: ignore state changes from parent
* @GST_ELEMENT_FLAG_SINK: the element is a sink
* @GST_ELEMENT_FLAG_SOURCE: the element is a source.
* @GST_ELEMENT_FLAG_PROVIDE_CLOCK: the element can provide a clock
* @GST_ELEMENT_FLAG_REQUIRE_CLOCK: the element requires a clock
* @GST_ELEMENT_FLAG_INDEXABLE: the element can use an index
* @GST_ELEMENT_FLAG_LAST: offset to define more flags
*
* The standard flags that an element may have.
*/
typedef enum
{
GST_ELEMENT_FLAG_LOCKED_STATE = (GST_OBJECT_FLAG_LAST << 0),
GST_ELEMENT_FLAG_SINK = (GST_OBJECT_FLAG_LAST << 1),
GST_ELEMENT_FLAG_SOURCE = (GST_OBJECT_FLAG_LAST << 2),
GST_ELEMENT_FLAG_PROVIDE_CLOCK = (GST_OBJECT_FLAG_LAST << 3),
GST_ELEMENT_FLAG_REQUIRE_CLOCK = (GST_OBJECT_FLAG_LAST << 4),
GST_ELEMENT_FLAG_INDEXABLE = (GST_OBJECT_FLAG_LAST << 5),
/* padding */
GST_ELEMENT_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 10)
} GstElementFlags;
/**
* GST_ELEMENT_IS_LOCKED_STATE:
* @elem: A #GstElement to query
*
* Check if the element is in the locked state and therefore will ignore state
* changes from its parent object.
*/
#define GST_ELEMENT_IS_LOCKED_STATE(elem) (GST_OBJECT_FLAG_IS_SET(elem,GST_ELEMENT_FLAG_LOCKED_STATE))
/**
* GST_ELEMENT_NAME:
* @elem: A #GstElement to query
*
* Gets the name of this element. This is not thread-safe by default
* (i.e. you will have to make sure the object lock is taken yourself).
* If in doubt use gst_element_get_name() instead.
*/
#define GST_ELEMENT_NAME(elem) (GST_OBJECT_NAME(elem))
/**
* GST_ELEMENT_PARENT:
* @elem: A #GstElement to query
*
* Get the parent object of this element. This is not thread-safe by default
* (i.e. you will have to make sure the object lock is taken yourself).
* If in doubt use gst_object_get_parent() instead.
*/
#define GST_ELEMENT_PARENT(elem) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(elem)))
/**
* GST_ELEMENT_BUS:
* @elem: A #GstElement to query
*
* Get the message bus of this element. This is not thread-safe by default
* (i.e. you will have to make sure the object lock is taken yourself).
* If in doubt use gst_element_get_bus() instead.
*/
#define GST_ELEMENT_BUS(elem) (GST_ELEMENT_CAST(elem)->bus)
/**
* GST_ELEMENT_CLOCK:
* @elem: A #GstElement to query
*
* Get the clock of this element.This is not thread-safe by default
* (i.e. you will have to make sure it is safe yourself).
* If in doubt use gst_element_get_clock() instead.
*/
#define GST_ELEMENT_CLOCK(elem) (GST_ELEMENT_CAST(elem)->clock)
/**
* GST_ELEMENT_PADS:
* @elem: A #GstElement to query
*
* Get the pads of this elements.
*/
#define GST_ELEMENT_PADS(elem) (GST_ELEMENT_CAST(elem)->pads)
/**
* GST_ELEMENT_START_TIME:
* @elem: a #GstElement to return the start time for.
*
* This macro returns the start_time of the @elem. The start_time is the
* running_time of the pipeline when the element went to PAUSED.
*/
#define GST_ELEMENT_START_TIME(elem) (GST_ELEMENT_CAST(elem)->start_time)
GstStructure *gst_make_element_message_details (const char *name, ...);
#define GST_ELEMENT_MESSAGE_MAKE_DETAILS(args) gst_make_element_message_details args
/**
* GST_ELEMENT_FLOW_ERROR:
* @el: the element that generates the error
* @flow_return: the GstFlowReturn leading to that ERROR message
*
* Utility function that elements can use in case they encountered a fatal
* data processing error due to wrong flow processing.
*
* Since: 1.10
*/
#define GST_ELEMENT_FLOW_ERROR(el,flow_return) \
G_STMT_START { \
GST_ELEMENT_ERROR_WITH_DETAILS (el, STREAM, FAILED, \
("Internal data stream error."), \
("streaming stopped, reason %s (%d)", gst_flow_get_name (flow_return), flow_return), \
("flow-return", G_TYPE_INT, flow_return, NULL));\
} G_STMT_END
/**
* GST_ELEMENT_ERROR_WITH_DETAILS:
* @el: the element that generates the error
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
* @args: optional name, type, value triplets, which will be stored
* in the associated GstStructure. NULL terminator required.
* Must be enclosed within parentheses.
*
* Utility function that elements can use in case they encountered a fatal
* data processing error. The pipeline will post an error message and the
* application will be requested to stop further media processing.
*
* Since: 1.10
*/
#define GST_ELEMENT_ERROR_WITH_DETAILS(el,domain,code,text,debug,args) \
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_WARNING_OBJECT (el, "error: %s", __txt); \
if (__dbg) \
GST_WARNING_OBJECT (el, "error: %s", __dbg); \
gst_element_message_full_with_details (GST_ELEMENT(el), \
GST_MESSAGE_ERROR, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
} G_STMT_END
/**
* GST_ELEMENT_ERROR:
* @el: the element that generates the error
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
*
* Utility function that elements can use in case they encountered a fatal
* data processing error. The pipeline will post an error message and the
* application will be requested to stop further media processing.
*/
#define GST_ELEMENT_ERROR(el,domain,code,text,debug) \
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_WARNING_OBJECT (el, "error: %s", __txt); \
if (__dbg) \
GST_WARNING_OBJECT (el, "error: %s", __dbg); \
gst_element_message_full (GST_ELEMENT(el), \
GST_MESSAGE_ERROR, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__); \
} G_STMT_END
/**
* GST_ELEMENT_WARNING_WITH_DETAILS:
* @el: the element that generates the warning
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
* @args: optional name, type, value triplets, which will be stored
* in the associated GstStructure. NULL terminator required.
* Must be enclosed within parentheses.
*
* Utility function that elements can use in case they encountered a non-fatal
* data processing problem. The pipeline will post a warning message and the
* application will be informed.
*
* Since: 1.10
*/
#define GST_ELEMENT_WARNING_WITH_DETAILS(el, domain, code, text, debug, args)\
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_WARNING_OBJECT (el, "warning: %s", __txt); \
if (__dbg) \
GST_WARNING_OBJECT (el, "warning: %s", __dbg); \
gst_element_message_full_with_details (GST_ELEMENT(el), \
GST_MESSAGE_WARNING, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
} G_STMT_END
/**
* GST_ELEMENT_WARNING:
* @el: the element that generates the warning
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
*
* Utility function that elements can use in case they encountered a non-fatal
* data processing problem. The pipeline will post a warning message and the
* application will be informed.
*/
#define GST_ELEMENT_WARNING(el, domain, code, text, debug) \
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_WARNING_OBJECT (el, "warning: %s", __txt); \
if (__dbg) \
GST_WARNING_OBJECT (el, "warning: %s", __dbg); \
gst_element_message_full (GST_ELEMENT(el), \
GST_MESSAGE_WARNING, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__); \
} G_STMT_END
/**
* GST_ELEMENT_INFO_WITH_DETAILS:
* @el: the element that generates the information
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
* @args: optional name, type, value triplets, which will be stored
* in the associated GstStructure. NULL terminator required.
* Must be enclosed within parentheses.
*
* Utility function that elements can use in case they want to inform
* the application of something noteworthy that is not an error.
* The pipeline will post a info message and the
* application will be informed.
* Optional name, type, value triplets may be supplied, and will be stored
* in the associated GstStructure. NULL terminator required.
*
* Since: 1.10
*/
#define GST_ELEMENT_INFO_WITH_DETAILS(el, domain, code, text, debug, args) \
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_INFO_OBJECT (el, "info: %s", __txt); \
if (__dbg) \
GST_INFO_OBJECT (el, "info: %s", __dbg); \
gst_element_message_full_with_details (GST_ELEMENT(el), \
GST_MESSAGE_INFO, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__, GST_ELEMENT_MESSAGE_MAKE_DETAILS(args)); \
} G_STMT_END
/**
* GST_ELEMENT_INFO:
* @el: the element that generates the information
* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
* @code: error code defined for that domain (see #gstreamer-GstGError)
* @text: the message to display (format string and args enclosed in
parentheses)
* @debug: debugging information for the message (format string and args
enclosed in parentheses)
*
* Utility function that elements can use in case they want to inform
* the application of something noteworthy that is not an error.
* The pipeline will post a info message and the
* application will be informed.
*/
#define GST_ELEMENT_INFO(el, domain, code, text, debug) \
G_STMT_START { \
gchar *__txt = _gst_element_error_printf text; \
gchar *__dbg = _gst_element_error_printf debug; \
if (__txt) \
GST_INFO_OBJECT (el, "info: %s", __txt); \
if (__dbg) \
GST_INFO_OBJECT (el, "info: %s", __dbg); \
gst_element_message_full (GST_ELEMENT(el), \
GST_MESSAGE_INFO, GST_ ## domain ## _ERROR, \
GST_ ## domain ## _ERROR_ ## code, __txt, __dbg, __FILE__, \
GST_FUNCTION, __LINE__); \
} G_STMT_END
/* the state change mutexes and conds */
/**
* GST_STATE_GET_LOCK:
* @elem: a #GstElement
*
* Get a reference to the state lock of @elem.
* This lock is used by the core. It is taken while getting or setting
* the state, during state changes, and while finalizing.
*/
#define GST_STATE_GET_LOCK(elem) (&(GST_ELEMENT_CAST(elem)->state_lock))
/**
* GST_STATE_GET_COND:
* @elem: a #GstElement
*
* Get the conditional used to signal the completion of a state change.
*/
#define GST_STATE_GET_COND(elem) (&GST_ELEMENT_CAST(elem)->state_cond)
#define GST_STATE_LOCK(elem) g_rec_mutex_lock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_TRYLOCK(elem) g_rec_mutex_trylock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_UNLOCK(elem) g_rec_mutex_unlock(GST_STATE_GET_LOCK(elem))
#define GST_STATE_WAIT(elem) g_cond_wait (GST_STATE_GET_COND (elem), \
GST_OBJECT_GET_LOCK (elem))
#define GST_STATE_WAIT_UNTIL(elem, end_time) g_cond_wait_until (GST_STATE_GET_COND (elem), \
GST_OBJECT_GET_LOCK (elem), end_time)
#define GST_STATE_SIGNAL(elem) g_cond_signal (GST_STATE_GET_COND (elem));
#define GST_STATE_BROADCAST(elem) g_cond_broadcast (GST_STATE_GET_COND (elem));
/**
* GstElement:
* @state_lock: Used to serialize execution of gst_element_set_state()
* @state_cond: Used to signal completion of a state change
* @state_cookie: Used to detect concurrent execution of
* gst_element_set_state() and gst_element_get_state()
* @target_state: the target state of an element as set by the application
* @current_state: the current state of an element
* @next_state: the next state of an element, can be #GST_STATE_VOID_PENDING if
* the element is in the correct state.
* @pending_state: the final state the element should go to, can be
* #GST_STATE_VOID_PENDING if the element is in the correct state
* @last_return: the last return value of an element state change
* @bus: the bus of the element. This bus is provided to the element by the
* parent element or the application. A #GstPipeline has a bus of its own.
* @clock: the clock of the element. This clock is usually provided to the
* element by the toplevel #GstPipeline.
* @base_time: the time of the clock right before the element is set to
* PLAYING. Subtracting @base_time from the current clock time in the PLAYING
* state will yield the running_time against the clock.
* @start_time: the running_time of the last PAUSED state
* @numpads: number of pads of the element, includes both source and sink pads.
* @pads: (element-type Gst.Pad): list of pads
* @numsrcpads: number of source pads of the element.
* @srcpads: (element-type Gst.Pad): list of source pads
* @numsinkpads: number of sink pads of the element.
* @sinkpads: (element-type Gst.Pad): list of sink pads
* @pads_cookie: updated whenever the a pad is added or removed
* @contexts: (element-type Gst.Context): list of contexts
*
* GStreamer element abstract base class.
*/
struct _GstElement
{
GstObject object;
/*< public >*/ /* with LOCK */
GRecMutex state_lock;
/* element state */
GCond state_cond;
guint32 state_cookie;
GstState target_state;
GstState current_state;
GstState next_state;
GstState pending_state;
GstStateChangeReturn last_return;
GstBus *bus;
/* allocated clock */
GstClock *clock;
GstClockTimeDiff base_time; /* NULL/READY: 0 - PAUSED: current time - PLAYING: difference to clock */
GstClockTime start_time;
/* element pads, these lists can only be iterated while holding
* the LOCK or checking the cookie after each LOCK. */
guint16 numpads;
GList *pads;
guint16 numsrcpads;
GList *srcpads;
guint16 numsinkpads;
GList *sinkpads;
guint32 pads_cookie;
/* with object LOCK */
GList *contexts;
/*< private >*/
gpointer _gst_reserved[GST_PADDING-1];
};
/**
* GstElementClass:
* @parent_class: the parent class structure
* @metadata: metadata for elements of this class
* @elementfactory: the #GstElementFactory that creates these elements
* @padtemplates: a #GList of #GstPadTemplate
* @numpadtemplates: the number of padtemplates
* @pad_templ_cookie: changed whenever the padtemplates change
* @request_new_pad: called when a new pad is requested
* @release_pad: called when a request pad is to be released
* @get_state: get the state of the element
* @set_state: set a new state on the element
* @change_state: called by @set_state to perform an incremental state change
* @set_bus: set a #GstBus on the element
* @provide_clock: gets the #GstClock provided by the element
* @set_clock: set the #GstClock on the element
* @send_event: send a #GstEvent to the element
* @query: perform a #GstQuery on the element
* @state_changed: called immediately after a new state was set.
* @post_message: called when a message is posted on the element. Chain up to
* the parent class' handler to have it posted on the bus.
* @set_context: set a #GstContext on the element
*
* GStreamer element class. Override the vmethods to implement the element
* functionality.
*/
struct _GstElementClass
{
GstObjectClass parent_class;
/*< public >*/
/* the element metadata */
gpointer metadata;
/* factory that the element was created from */
GstElementFactory *elementfactory;
/* templates for our pads */
GList *padtemplates;
gint numpadtemplates;
guint32 pad_templ_cookie;
/*< private >*/
/* signal callbacks */
void (*pad_added) (GstElement *element, GstPad *pad);
void (*pad_removed) (GstElement *element, GstPad *pad);
void (*no_more_pads) (GstElement *element);
/*< public >*/
/* virtual methods for subclasses */
/* request/release pads */
/* FIXME 2.0 harmonize naming with gst_element_request_pad */
GstPad* (*request_new_pad) (GstElement *element, GstPadTemplate *templ,
const gchar* name, const GstCaps *caps);
void (*release_pad) (GstElement *element, GstPad *pad);
/* state changes */
GstStateChangeReturn (*get_state) (GstElement * element, GstState * state,
GstState * pending, GstClockTime timeout);
GstStateChangeReturn (*set_state) (GstElement *element, GstState state);
GstStateChangeReturn (*change_state) (GstElement *element, GstStateChange transition);
void (*state_changed) (GstElement *element, GstState oldstate,
GstState newstate, GstState pending);
/* bus */
void (*set_bus) (GstElement * element, GstBus * bus);
/* set/get clocks */
GstClock* (*provide_clock) (GstElement *element);
gboolean (*set_clock) (GstElement *element, GstClock *clock);
/* query functions */
gboolean (*send_event) (GstElement *element, GstEvent *event);
gboolean (*query) (GstElement *element, GstQuery *query);
gboolean (*post_message) (GstElement *element, GstMessage *message);
void (*set_context) (GstElement *element, GstContext *context);
/*< private >*/
gpointer _gst_reserved[GST_PADDING_LARGE-2];
};
/* element class pad templates */
void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ);
void gst_element_class_add_static_pad_template (GstElementClass *klass, GstStaticPadTemplate *static_templ);
GstPadTemplate* gst_element_class_get_pad_template (GstElementClass *element_class, const gchar *name);
GList* gst_element_class_get_pad_template_list (GstElementClass *element_class);
/* element class meta data */
void gst_element_class_set_metadata (GstElementClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
void gst_element_class_set_static_metadata (GstElementClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
void gst_element_class_add_metadata (GstElementClass * klass,
const gchar * key, const gchar * value);
void gst_element_class_add_static_metadata (GstElementClass * klass,
const gchar * key, const gchar * value);
const gchar * gst_element_class_get_metadata (GstElementClass * klass,
const gchar * key);
/* element instance */
GType gst_element_get_type (void);
/* basic name and parentage stuff from GstObject */
/**
* gst_element_get_name:
* @elem: a #GstElement to get the name of @elem.
*
* Returns a copy of the name of @elem.
* Caller should g_free() the return value after usage.
* For a nameless element, this returns %NULL, which you can safely g_free()
* as well.
*
* Returns: (transfer full) (nullable): the name of @elem. g_free()
* after usage. MT safe.
*
*/
#define gst_element_get_name(elem) gst_object_get_name(GST_OBJECT_CAST(elem))
/**
* gst_element_set_name:
* @elem: a #GstElement to set the name of.
* @name: the new name
*
* Sets the name of the element, getting rid of the old name if there was one.
*/
#define gst_element_set_name(elem,name) gst_object_set_name(GST_OBJECT_CAST(elem),name)
/**
* gst_element_get_parent:
* @elem: a #GstElement to get the parent of.
*
* Get the parent of an element.
*
* Returns: (transfer full): the parent of an element.
*/
#define gst_element_get_parent(elem) gst_object_get_parent(GST_OBJECT_CAST(elem))
/**
* gst_element_set_parent:
* @elem: a #GstElement to set the parent of.
* @parent: the new parent #GstObject of the element.
*
* Sets the parent of an element.
*/
#define gst_element_set_parent(elem,parent) gst_object_set_parent(GST_OBJECT_CAST(elem),parent)
/* clocking */
GstClock* gst_element_provide_clock (GstElement *element);
GstClock* gst_element_get_clock (GstElement *element);
gboolean gst_element_set_clock (GstElement *element, GstClock *clock);
void gst_element_set_base_time (GstElement *element, GstClockTime time);
GstClockTime gst_element_get_base_time (GstElement *element);
void gst_element_set_start_time (GstElement *element, GstClockTime time);
GstClockTime gst_element_get_start_time (GstElement *element);
/* bus */
void gst_element_set_bus (GstElement * element, GstBus * bus);
GstBus * gst_element_get_bus (GstElement * element);
/* context */
void gst_element_set_context (GstElement * element, GstContext * context);
GList * gst_element_get_contexts (GstElement * element);
GstContext * gst_element_get_context (GstElement * element, const gchar * context_type);
GstContext * gst_element_get_context_unlocked (GstElement * element, const gchar * context_type);
/* pad management */
gboolean gst_element_add_pad (GstElement *element, GstPad *pad);
gboolean gst_element_remove_pad (GstElement *element, GstPad *pad);
void gst_element_no_more_pads (GstElement *element);
GstPad* gst_element_get_static_pad (GstElement *element, const gchar *name);
GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name);
GstPad* gst_element_request_pad (GstElement *element, GstPadTemplate *templ,
const gchar * name, const GstCaps *caps);
void gst_element_release_request_pad (GstElement *element, GstPad *pad);
GstIterator * gst_element_iterate_pads (GstElement * element);
GstIterator * gst_element_iterate_src_pads (GstElement * element);
GstIterator * gst_element_iterate_sink_pads (GstElement * element);
/* event/query/format stuff */
gboolean gst_element_send_event (GstElement *element, GstEvent *event);
gboolean gst_element_seek (GstElement *element, gdouble rate,
GstFormat format, GstSeekFlags flags,
GstSeekType start_type, gint64 start,
GstSeekType stop_type, gint64 stop);
gboolean gst_element_query (GstElement *element, GstQuery *query);
/* messages */
gboolean gst_element_post_message (GstElement * element, GstMessage * message);
/* error handling */
/* gcc versions < 3.3 warn about NULL being passed as format to printf */
#if (!defined(__GNUC__) || (__GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 3))
gchar * _gst_element_error_printf (const gchar *format, ...);
#else
gchar * _gst_element_error_printf (const gchar *format, ...) G_GNUC_PRINTF (1, 2);
#endif
void gst_element_message_full (GstElement * element, GstMessageType type,
GQuark domain, gint code, gchar * text,
gchar * debug, const gchar * file,
const gchar * function, gint line);
void gst_element_message_full_with_details (GstElement * element, GstMessageType type,
GQuark domain, gint code, gchar * text,
gchar * debug, const gchar * file,
const gchar * function, gint line,
GstStructure * structure);
/* state management */
gboolean gst_element_is_locked_state (GstElement *element);
gboolean gst_element_set_locked_state (GstElement *element, gboolean locked_state);
gboolean gst_element_sync_state_with_parent (GstElement *element);
GstStateChangeReturn gst_element_get_state (GstElement * element,
GstState * state,
GstState * pending,
GstClockTime timeout);
GstStateChangeReturn gst_element_set_state (GstElement *element, GstState state);
void gst_element_abort_state (GstElement * element);
GstStateChangeReturn gst_element_change_state (GstElement * element,
GstStateChange transition);
GstStateChangeReturn gst_element_continue_state (GstElement * element,
GstStateChangeReturn ret);
void gst_element_lost_state (GstElement * element);
typedef void (*GstElementCallAsyncFunc) (GstElement * element,
gpointer user_data);
void gst_element_call_async (GstElement * element,
GstElementCallAsyncFunc func, gpointer user_data,
GDestroyNotify destroy_notify);
/* factory management */
GstElementFactory* gst_element_get_factory (GstElement *element);
/* utility functions */
gulong gst_element_add_property_notify_watch (GstElement * element,
const gchar * property_name,
gboolean include_value);
gulong gst_element_add_property_deep_notify_watch (GstElement * element,
const gchar * property_name,
gboolean include_value);
void gst_element_remove_property_notify_watch (GstElement * element,
gulong watch_id);
#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref)
#endif
G_END_DECLS
#endif /* __GST_ELEMENT_H__ */
Reference in a new issue View git blame Copy permalink