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dd831b8114
Elements should override GstElement::set_context() and also call gst_element_set_context() to keep this context up-to-date with the very latest context they internally use.
810 lines
34 KiB
C
810 lines
34 KiB
C
/* GStreamer
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* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
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* 2000,2004 Wim Taymans <wim@fluendo.com>
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*
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* gstelement.h: Header for GstElement
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Library General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Library General Public License for more details.
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*
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* You should have received a copy of the GNU Library General Public
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* License along with this library; if not, write to the
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* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
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* Boston, MA 02110-1301, USA.
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*/
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#ifndef __GST_ELEMENT_H__
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#define __GST_ELEMENT_H__
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/* gstelement.h and gstelementfactory.h include eachother */
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typedef struct _GstElement GstElement;
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typedef struct _GstElementClass GstElementClass;
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/* gstmessage.h needs State */
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/**
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* GstState:
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* @GST_STATE_VOID_PENDING: no pending state.
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* @GST_STATE_NULL : the NULL state or initial state of an element.
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* @GST_STATE_READY : the element is ready to go to PAUSED.
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* @GST_STATE_PAUSED : the element is PAUSED, it is ready to accept and
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* process data. Sink elements however only accept one
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* buffer and then block.
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* @GST_STATE_PLAYING : the element is PLAYING, the #GstClock is running and
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* the data is flowing.
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*
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* The possible states an element can be in. States can be changed using
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* gst_element_set_state() and checked using gst_element_get_state().
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*/
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typedef enum {
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GST_STATE_VOID_PENDING = 0,
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GST_STATE_NULL = 1,
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GST_STATE_READY = 2,
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GST_STATE_PAUSED = 3,
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GST_STATE_PLAYING = 4
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} GstState;
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#include <gst/gstconfig.h>
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#include <gst/gstobject.h>
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#include <gst/gstpad.h>
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#include <gst/gstbus.h>
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#include <gst/gstclock.h>
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#include <gst/gstelementfactory.h>
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#include <gst/gstplugin.h>
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#include <gst/gstpluginfeature.h>
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#include <gst/gstiterator.h>
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#include <gst/gstmessage.h>
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#include <gst/gstquery.h>
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#include <gst/gsttaglist.h>
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G_BEGIN_DECLS
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#define GST_TYPE_ELEMENT (gst_element_get_type ())
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#define GST_IS_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_ELEMENT))
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#define GST_IS_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_ELEMENT))
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#define GST_ELEMENT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), GST_TYPE_ELEMENT, GstElementClass))
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#define GST_ELEMENT(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_ELEMENT, GstElement))
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#define GST_ELEMENT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_ELEMENT, GstElementClass))
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#define GST_ELEMENT_CAST(obj) ((GstElement*)(obj))
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/**
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* GstStateChangeReturn:
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* @GST_STATE_CHANGE_FAILURE : the state change failed
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* @GST_STATE_CHANGE_SUCCESS : the state change succeeded
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* @GST_STATE_CHANGE_ASYNC : the state change will happen asynchronously
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* @GST_STATE_CHANGE_NO_PREROLL: the state change succeeded but the element
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* cannot produce data in %GST_STATE_PAUSED.
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* This typically happens with live sources.
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*
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* The possible return values from a state change function such as
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* gst_element_set_state(). Only @GST_STATE_CHANGE_FAILURE is a real failure.
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*/
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typedef enum {
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GST_STATE_CHANGE_FAILURE = 0,
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GST_STATE_CHANGE_SUCCESS = 1,
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GST_STATE_CHANGE_ASYNC = 2,
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GST_STATE_CHANGE_NO_PREROLL = 3
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} GstStateChangeReturn;
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/* NOTE: this probably should be done with an #ifdef to decide
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* whether to safe-cast or to just do the non-checking cast.
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*/
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/**
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* GST_STATE:
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* @elem: a #GstElement to return state for.
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*
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* This macro returns the current #GstState of the element.
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*/
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#define GST_STATE(elem) (GST_ELEMENT_CAST(elem)->current_state)
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/**
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* GST_STATE_NEXT:
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* @elem: a #GstElement to return the next state for.
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*
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* This macro returns the next #GstState of the element.
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*/
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#define GST_STATE_NEXT(elem) (GST_ELEMENT_CAST(elem)->next_state)
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/**
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* GST_STATE_PENDING:
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* @elem: a #GstElement to return the pending state for.
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*
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* This macro returns the currently pending #GstState of the element.
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*/
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#define GST_STATE_PENDING(elem) (GST_ELEMENT_CAST(elem)->pending_state)
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/**
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* GST_STATE_TARGET:
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* @elem: a #GstElement to return the target state for.
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*
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* This macro returns the target #GstState of the element.
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*/
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#define GST_STATE_TARGET(elem) (GST_ELEMENT_CAST(elem)->target_state)
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/**
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* GST_STATE_RETURN:
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* @elem: a #GstElement to return the last state result for.
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*
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* This macro returns the last #GstStateChangeReturn value.
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*/
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#define GST_STATE_RETURN(elem) (GST_ELEMENT_CAST(elem)->last_return)
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#define __GST_SIGN(val) ((val) < 0 ? -1 : ((val) > 0 ? 1 : 0))
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/**
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* GST_STATE_GET_NEXT:
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* @cur: A starting #GstState
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* @pending: A target #GstState
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*
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* Given a current state @cur and a target state @pending, calculate the next (intermediate)
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* #GstState.
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*/
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#define GST_STATE_GET_NEXT(cur,pending) ((GstState)((cur) + __GST_SIGN ((gint)(pending) - (gint)(cur))))
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/**
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* GST_STATE_TRANSITION:
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* @cur: A current state
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* @next: A next state
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*
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* Given a current state @cur and a next state @next, calculate the associated
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* #GstStateChange transition.
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*/
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#define GST_STATE_TRANSITION(cur,next) ((GstStateChange)(((cur)<<3)|(next)))
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/**
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* GST_STATE_TRANSITION_CURRENT:
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* @trans: A #GstStateChange
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*
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* Given a state transition @trans, extract the current #GstState.
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*/
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#define GST_STATE_TRANSITION_CURRENT(trans) ((GstState)((trans)>>3))
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/**
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* GST_STATE_TRANSITION_NEXT:
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* @trans: A #GstStateChange
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*
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* Given a state transition @trans, extract the next #GstState.
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*/
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#define GST_STATE_TRANSITION_NEXT(trans) ((GstState)((trans)&0x7))
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/**
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* GstStateChange:
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* @GST_STATE_CHANGE_NULL_TO_READY : state change from NULL to READY.
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* <itemizedlist>
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* <listitem><para>
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* The element must check if the resources it needs are available. Device
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* sinks and -sources typically try to probe the device to constrain their
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* caps.
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* </para></listitem>
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* <listitem><para>
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* The element opens the device (in case feature need to be probed).
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* </para></listitem>
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* </itemizedlist>
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* @GST_STATE_CHANGE_READY_TO_PAUSED : state change from READY to PAUSED.
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* <itemizedlist>
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* <listitem><para>
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* The element pads are activated in order to receive data in PAUSED.
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* Streaming threads are started.
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* </para></listitem>
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* <listitem><para>
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* Some elements might need to return %GST_STATE_CHANGE_ASYNC and complete
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* the state change when they have enough information. It is a requirement
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* for sinks to return %GST_STATE_CHANGE_ASYNC and complete the state change
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* when they receive the first buffer or %GST_EVENT_EOS (preroll).
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* Sinks also block the dataflow when in PAUSED.
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* </para></listitem>
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* <listitem><para>
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* A pipeline resets the running_time to 0.
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* </para></listitem>
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* <listitem><para>
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* Live sources return %GST_STATE_CHANGE_NO_PREROLL and don't generate data.
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* </para></listitem>
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* </itemizedlist>
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* @GST_STATE_CHANGE_PAUSED_TO_PLAYING: state change from PAUSED to PLAYING.
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* <itemizedlist>
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* <listitem><para>
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* Most elements ignore this state change.
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* </para></listitem>
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* <listitem><para>
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* The pipeline selects a #GstClock and distributes this to all the children
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* before setting them to PLAYING. This means that it is only alowed to
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* synchronize on the #GstClock in the PLAYING state.
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* </para></listitem>
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* <listitem><para>
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* The pipeline uses the #GstClock and the running_time to calculate the
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* base_time. The base_time is distributed to all children when performing
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* the state change.
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* </para></listitem>
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* <listitem><para>
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* Sink elements stop blocking on the preroll buffer or event and start
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* rendering the data.
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* </para></listitem>
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* <listitem><para>
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* Sinks can post %GST_MESSAGE_EOS in the PLAYING state. It is not allowed
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* to post %GST_MESSAGE_EOS when not in the PLAYING state.
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* </para></listitem>
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* <listitem><para>
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* While streaming in PAUSED or PLAYING elements can create and remove
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* sometimes pads.
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* </para></listitem>
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* <listitem><para>
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* Live sources start generating data and return %GST_STATE_CHANGE_SUCCESS.
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* </para></listitem>
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* </itemizedlist>
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* @GST_STATE_CHANGE_PLAYING_TO_PAUSED: state change from PLAYING to PAUSED.
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* <itemizedlist>
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* <listitem><para>
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* Most elements ignore this state change.
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* </para></listitem>
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* <listitem><para>
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* The pipeline calculates the running_time based on the last selected
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* #GstClock and the base_time. It stores this information to continue
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* playback when going back to the PLAYING state.
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* </para></listitem>
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* <listitem><para>
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* Sinks unblock any #GstClock wait calls.
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* </para></listitem>
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* <listitem><para>
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* When a sink does not have a pending buffer to play, it returns
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* %GST_STATE_CHANGE_ASYNC from this state change and completes the state
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* change when it receives a new buffer or an %GST_EVENT_EOS.
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* </para></listitem>
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* <listitem><para>
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* Any queued %GST_MESSAGE_EOS items are removed since they will be reposted
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* when going back to the PLAYING state. The EOS messages are queued in
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* #GstBin containers.
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* </para></listitem>
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* <listitem><para>
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* Live sources stop generating data and return %GST_STATE_CHANGE_NO_PREROLL.
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* </para></listitem>
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* </itemizedlist>
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* @GST_STATE_CHANGE_PAUSED_TO_READY : state change from PAUSED to READY.
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* <itemizedlist>
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* <listitem><para>
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* Sinks unblock any waits in the preroll.
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* </para></listitem>
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* <listitem><para>
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* Elements unblock any waits on devices
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* </para></listitem>
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* <listitem><para>
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* Chain or get_range functions return %GST_FLOW_FLUSHING.
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* </para></listitem>
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* <listitem><para>
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* The element pads are deactivated so that streaming becomes impossible and
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* all streaming threads are stopped.
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* </para></listitem>
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* <listitem><para>
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* The sink forgets all negotiated formats
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* </para></listitem>
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* <listitem><para>
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* Elements remove all sometimes pads
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* </para></listitem>
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* </itemizedlist>
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* @GST_STATE_CHANGE_READY_TO_NULL : state change from READY to NULL.
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* <itemizedlist>
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* <listitem><para>
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* Elements close devices
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* </para></listitem>
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* <listitem><para>
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* Elements reset any internal state.
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* </para></listitem>
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* </itemizedlist>
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*
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* These are the different state changes an element goes through.
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* %GST_STATE_NULL ⇒ %GST_STATE_PLAYING is called an upwards state change
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* and %GST_STATE_PLAYING ⇒ %GST_STATE_NULL a downwards state change.
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*/
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typedef enum /*< flags=0 >*/
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{
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GST_STATE_CHANGE_NULL_TO_READY = (GST_STATE_NULL<<3) | GST_STATE_READY,
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GST_STATE_CHANGE_READY_TO_PAUSED = (GST_STATE_READY<<3) | GST_STATE_PAUSED,
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GST_STATE_CHANGE_PAUSED_TO_PLAYING = (GST_STATE_PAUSED<<3) | GST_STATE_PLAYING,
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GST_STATE_CHANGE_PLAYING_TO_PAUSED = (GST_STATE_PLAYING<<3) | GST_STATE_PAUSED,
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GST_STATE_CHANGE_PAUSED_TO_READY = (GST_STATE_PAUSED<<3) | GST_STATE_READY,
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GST_STATE_CHANGE_READY_TO_NULL = (GST_STATE_READY<<3) | GST_STATE_NULL
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} GstStateChange;
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/**
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* GstElementFlags:
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* @GST_ELEMENT_FLAG_LOCKED_STATE: ignore state changes from parent
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* @GST_ELEMENT_FLAG_SINK: the element is a sink
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* @GST_ELEMENT_FLAG_SOURCE: the element is a source.
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* @GST_ELEMENT_FLAG_PROVIDE_CLOCK: the element can provide a clock
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* @GST_ELEMENT_FLAG_REQUIRE_CLOCK: the element requires a clock
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* @GST_ELEMENT_FLAG_INDEXABLE: the element can use an index
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* @GST_ELEMENT_FLAG_LAST: offset to define more flags
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*
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* The standard flags that an element may have.
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*/
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typedef enum
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{
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GST_ELEMENT_FLAG_LOCKED_STATE = (GST_OBJECT_FLAG_LAST << 0),
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GST_ELEMENT_FLAG_SINK = (GST_OBJECT_FLAG_LAST << 1),
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GST_ELEMENT_FLAG_SOURCE = (GST_OBJECT_FLAG_LAST << 2),
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GST_ELEMENT_FLAG_PROVIDE_CLOCK = (GST_OBJECT_FLAG_LAST << 3),
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GST_ELEMENT_FLAG_REQUIRE_CLOCK = (GST_OBJECT_FLAG_LAST << 4),
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GST_ELEMENT_FLAG_INDEXABLE = (GST_OBJECT_FLAG_LAST << 5),
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/* padding */
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GST_ELEMENT_FLAG_LAST = (GST_OBJECT_FLAG_LAST << 10)
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} GstElementFlags;
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/**
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* GST_ELEMENT_IS_LOCKED_STATE:
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* @elem: A #GstElement to query
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*
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* Check if the element is in the locked state and therefore will ignore state
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* changes from its parent object.
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*/
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#define GST_ELEMENT_IS_LOCKED_STATE(elem) (GST_OBJECT_FLAG_IS_SET(elem,GST_ELEMENT_FLAG_LOCKED_STATE))
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/**
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* GST_ELEMENT_NAME:
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* @elem: A #GstElement to query
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*
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* Gets the name of this element. Use only in core as this is not
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* ABI-compatible. Others use gst_element_get_name()
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*/
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#define GST_ELEMENT_NAME(elem) (GST_OBJECT_NAME(elem))
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/**
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* GST_ELEMENT_PARENT:
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* @elem: A #GstElement to query
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*
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* Get the parent object of this element.
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*/
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#define GST_ELEMENT_PARENT(elem) (GST_ELEMENT_CAST(GST_OBJECT_PARENT(elem)))
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/**
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* GST_ELEMENT_BUS:
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* @elem: A #GstElement to query
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*
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* Get the message bus of this element.
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*/
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#define GST_ELEMENT_BUS(elem) (GST_ELEMENT_CAST(elem)->bus)
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/**
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* GST_ELEMENT_CLOCK:
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* @elem: A #GstElement to query
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*
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* Get the clock of this element
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*/
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#define GST_ELEMENT_CLOCK(elem) (GST_ELEMENT_CAST(elem)->clock)
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/**
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* GST_ELEMENT_PADS:
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* @elem: A #GstElement to query
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*
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* Get the pads of this elements.
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*/
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#define GST_ELEMENT_PADS(elem) (GST_ELEMENT_CAST(elem)->pads)
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/**
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* GST_ELEMENT_START_TIME:
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* @elem: a #GstElement to return the start time for.
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*
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* This macro returns the start_time of the @elem. The start_time is the
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* running_time of the pipeline when the element went to PAUSED.
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*/
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#define GST_ELEMENT_START_TIME(elem) (GST_ELEMENT_CAST(elem)->start_time)
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/**
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* GST_ELEMENT_ERROR:
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* @el: the element that generates the error
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* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
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* @code: error code defined for that domain (see #gstreamer-GstGError)
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* @text: the message to display (format string and args enclosed in
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parentheses)
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* @debug: debugging information for the message (format string and args
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enclosed in parentheses)
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*
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* Utility function that elements can use in case they encountered a fatal
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* data processing error. The pipeline will post an error message and the
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* application will be requested to stop further media processing.
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*/
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#define GST_ELEMENT_ERROR(el, domain, code, text, debug) \
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G_STMT_START { \
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gchar *__txt = _gst_element_error_printf text; \
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gchar *__dbg = _gst_element_error_printf debug; \
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if (__txt) \
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GST_WARNING_OBJECT (el, "error: %s", __txt); \
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if (__dbg) \
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GST_WARNING_OBJECT (el, "error: %s", __dbg); \
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gst_element_message_full (GST_ELEMENT(el), GST_MESSAGE_ERROR, \
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GST_ ## domain ## _ERROR, GST_ ## domain ## _ERROR_ ## code, \
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__txt, __dbg, __FILE__, GST_FUNCTION, __LINE__); \
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} G_STMT_END
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/**
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* GST_ELEMENT_WARNING:
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* @el: the element that generates the warning
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* @domain: like CORE, LIBRARY, RESOURCE or STREAM (see #gstreamer-GstGError)
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* @code: error code defined for that domain (see #gstreamer-GstGError)
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* @text: the message to display (format string and args enclosed in
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parentheses)
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* @debug: debugging information for the message (format string and args
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enclosed in parentheses)
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*
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* Utility function that elements can use in case they encountered a non-fatal
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* data processing problem. The pipeline will post a warning message and the
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* application will be informed.
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*/
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|
#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:
|
|
* @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_UNLOCK_FULL(elem) g_rec_mutex_unlock_full(GST_STATE_GET_LOCK(elem))
|
|
#define GST_STATE_LOCK_FULL(elem,t) g_rec_mutex_lock_full(GST_STATE_GET_LOCK(elem), t)
|
|
#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
|
|
*
|
|
* 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;
|
|
|
|
GstContext *context;
|
|
|
|
/*< 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 */
|
|
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);
|
|
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): 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);
|
|
GstContext * gst_element_get_context (GstElement * element);
|
|
|
|
/* 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(GST_USING_PRINTF_EXTENSION) || !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);
|
|
|
|
/* 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);
|
|
|
|
/* factory management */
|
|
GstElementFactory* gst_element_get_factory (GstElement *element);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __GST_ELEMENT_H__ */
|