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gstreamer/gst/gstelement.h
Niels De Graef 09141c6e1f Use G_DEFINE_AUTOPTR_CLEANUP_FUNC unconditionally 
Since we started depending on GLib 2.44, we can be sure this macro is
defined (it will be a no-op on compilers that don't support it). For
plugins we should just start using `G_DECLARE_FINAL_TYPE` which means
we no longer need the macro there, but for most types in core we don't
want to break ABI, which means it's better to just keep it like it is
(and use the `#ifdef` instead).
2019-06-04 08:50:59 +02:00

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/* 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 each other */
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.
* @GST_STATE_CHANGE_NULL_TO_NULL : state change from NULL to NULL. (Since: 1.14)
* @GST_STATE_CHANGE_READY_TO_READY : state change from READY to READY,
* This might happen when going to PAUSED asynchronously failed, in that case
* elements should make sure they are in a proper, coherent READY state. (Since: 1.14)
* @GST_STATE_CHANGE_PAUSED_TO_PAUSED : state change from PAUSED to PAUSED.
* This might happen when elements were in PLAYING state and 'lost state',
* they should make sure to go back to real 'PAUSED' state (prerolling for example). (Since: 1.14)
* @GST_STATE_CHANGE_PLAYING_TO_PLAYING : state change from PLAYING to PLAYING. (Since: 1.14)
*
* 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,
GST_STATE_CHANGE_NULL_TO_NULL = (GST_STATE_NULL<<3) | GST_STATE_NULL,
GST_STATE_CHANGE_READY_TO_READY = (GST_STATE_READY<<3) | GST_STATE_READY,
GST_STATE_CHANGE_PAUSED_TO_PAUSED = (GST_STATE_PAUSED<<3) | GST_STATE_PAUSED,
GST_STATE_CHANGE_PLAYING_TO_PLAYING = (GST_STATE_PLAYING<<3) | GST_STATE_PLAYING
} 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)
GST_API
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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 [GstGError](gsterror))
* @code: error code defined for that domain (see [GstGError](gsterror))
* @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 */
GST_API
void gst_element_class_add_pad_template (GstElementClass *klass, GstPadTemplate *templ);
GST_API
void gst_element_class_add_static_pad_template (GstElementClass *klass, GstStaticPadTemplate *static_templ);
GST_API
void gst_element_class_add_static_pad_template_with_gtype (GstElementClass *klass,
GstStaticPadTemplate *static_templ,
GType pad_type);
GST_API
GstPadTemplate* gst_element_class_get_pad_template (GstElementClass *element_class, const gchar *name);
GST_API
GList* gst_element_class_get_pad_template_list (GstElementClass *element_class);
/* element class meta data */
GST_API
void gst_element_class_set_metadata (GstElementClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
GST_API
void gst_element_class_set_static_metadata (GstElementClass *klass,
const gchar *longname,
const gchar *classification,
const gchar *description,
const gchar *author);
GST_API
void gst_element_class_add_metadata (GstElementClass * klass,
const gchar * key, const gchar * value);
GST_API
void gst_element_class_add_static_metadata (GstElementClass * klass,
const gchar * key, const gchar * value);
GST_API
const gchar * gst_element_class_get_metadata (GstElementClass * klass,
const gchar * key);
/* element instance */
GST_API
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 */
GST_API
GstClock* gst_element_provide_clock (GstElement *element);
GST_API
GstClock* gst_element_get_clock (GstElement *element);
GST_API
gboolean gst_element_set_clock (GstElement *element, GstClock *clock);
GST_API
void gst_element_set_base_time (GstElement *element, GstClockTime time);
GST_API
GstClockTime gst_element_get_base_time (GstElement *element);
GST_API
void gst_element_set_start_time (GstElement *element, GstClockTime time);
GST_API
GstClockTime gst_element_get_start_time (GstElement *element);
/* bus */
GST_API
void gst_element_set_bus (GstElement * element, GstBus * bus);
GST_API
GstBus * gst_element_get_bus (GstElement * element);
/* context */
GST_API
void gst_element_set_context (GstElement * element, GstContext * context);
GST_API
GList * gst_element_get_contexts (GstElement * element);
GST_API
GstContext * gst_element_get_context (GstElement * element, const gchar * context_type);
GST_API
GstContext * gst_element_get_context_unlocked (GstElement * element, const gchar * context_type);
/* pad management */
GST_API
gboolean gst_element_add_pad (GstElement *element, GstPad *pad);
GST_API
gboolean gst_element_remove_pad (GstElement *element, GstPad *pad);
GST_API
void gst_element_no_more_pads (GstElement *element);
GST_API
GstPad* gst_element_get_static_pad (GstElement *element, const gchar *name);
GST_API
GstPad* gst_element_get_request_pad (GstElement *element, const gchar *name);
GST_API
GstPad* gst_element_request_pad (GstElement *element, GstPadTemplate *templ,
const gchar * name, const GstCaps *caps);
GST_API
void gst_element_release_request_pad (GstElement *element, GstPad *pad);
GST_API
GstIterator * gst_element_iterate_pads (GstElement * element);
GST_API
GstIterator * gst_element_iterate_src_pads (GstElement * element);
GST_API
GstIterator * gst_element_iterate_sink_pads (GstElement * element);
/**
* GstElementForeachPadFunc:
* @element: the #GstElement
* @pad: a #GstPad
* @user_data: user data passed to the foreach function
*
* Function called for each pad when using gst_element_foreach_sink_pad(),
* gst_element_foreach_src_pad(), or gst_element_foreach_pad().
*
* Returns: %FALSE to stop iterating pads, %TRUE to continue
*
* Since: 1.14
*/
typedef gboolean (*GstElementForeachPadFunc) (GstElement * element,
GstPad * pad,
gpointer user_data);
GST_API
gboolean gst_element_foreach_sink_pad (GstElement * element,
GstElementForeachPadFunc func,
gpointer user_data);
GST_API
gboolean gst_element_foreach_src_pad (GstElement * element,
GstElementForeachPadFunc func,
gpointer user_data);
GST_API
gboolean gst_element_foreach_pad (GstElement * element,
GstElementForeachPadFunc func,
gpointer user_data);
/* event/query/format stuff */
GST_API
gboolean gst_element_send_event (GstElement *element, GstEvent *event);
GST_API
gboolean gst_element_seek (GstElement *element, gdouble rate,
GstFormat format, GstSeekFlags flags,
GstSeekType start_type, gint64 start,
GstSeekType stop_type, gint64 stop);
GST_API
gboolean gst_element_query (GstElement *element, GstQuery *query);
/* messages */
GST_API
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))
GST_API
gchar * _gst_element_error_printf (const gchar *format, ...);
#else
GST_API
gchar * _gst_element_error_printf (const gchar *format, ...) G_GNUC_PRINTF (1, 2);
#endif
GST_API
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);
GST_API
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 */
GST_API
gboolean gst_element_is_locked_state (GstElement *element);
GST_API
gboolean gst_element_set_locked_state (GstElement *element, gboolean locked_state);
GST_API
gboolean gst_element_sync_state_with_parent (GstElement *element);
GST_API
GstStateChangeReturn gst_element_get_state (GstElement * element,
GstState * state,
GstState * pending,
GstClockTime timeout);
GST_API
GstStateChangeReturn gst_element_set_state (GstElement *element, GstState state);
GST_API
void gst_element_abort_state (GstElement * element);
GST_API
GstStateChangeReturn gst_element_change_state (GstElement * element,
GstStateChange transition);
GST_API
GstStateChangeReturn gst_element_continue_state (GstElement * element,
GstStateChangeReturn ret);
GST_API
void gst_element_lost_state (GstElement * element);
/**
* GstElementCallAsyncFunc:
* @element: The #GstElement this function has been called against
* @user_data: Data passed in the function where that callback has been passed
*
* Callback prototype used in #gst_element_call_async
*/
typedef void (*GstElementCallAsyncFunc) (GstElement * element,
gpointer user_data);
GST_API
void gst_element_call_async (GstElement * element,
GstElementCallAsyncFunc func, gpointer user_data,
GDestroyNotify destroy_notify);
/* factory management */
GST_API
GstElementFactory* gst_element_get_factory (GstElement *element);
/* utility functions */
GST_API
gulong gst_element_add_property_notify_watch (GstElement * element,
const gchar * property_name,
gboolean include_value);
GST_API
gulong gst_element_add_property_deep_notify_watch (GstElement * element,
const gchar * property_name,
gboolean include_value);
GST_API
void gst_element_remove_property_notify_watch (GstElement * element,
gulong watch_id);
GST_API
GstPadTemplate* gst_element_get_pad_template (GstElement *element, const gchar *name);
GST_API
GList* gst_element_get_pad_template_list (GstElement *element);
GST_API
const gchar * gst_element_get_metadata (GstElement * element, const gchar * key);
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstElement, gst_object_unref)
G_END_DECLS
#endif /* __GST_ELEMENT_H__ */
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