gstreamer/docs/gst/tmpl/gstelement.sgml

<!-- ##### SECTION Title ##### -->
GstElement

<!-- ##### SECTION Short_Description ##### -->
Abstract base class for all pipeline elements

<!-- ##### SECTION Long_Description ##### -->
<para>
GstElement is the base class needed to construct an element that can be
used in a GStreamer pipeline.  As such, it is not a functional entity, and
cannot do anything when placed in a pipeline.
</para>

<para>
The name of a GstElement can be get with gst_element_get_name() and set with
gst_element_set_name().  For speed, GST_ELEMENT_NAME() can be used in the 
core.
Do not use this in plug-ins or applications in order to retain ABI 
compatibility.
</para>

<para>
All elements have pads (of the type #GstPad).  These pads link to pads on
other elements.  Buffers flow between these linked pads.
A GstElement has a GList of #GstPad structures for all their input (or sink)
and output (or source) pads.  
Core and plug-in writers can add and remove pads with gst_element_add_pad()
and gst_element_remove_pad().
Application writers can manipulate ghost pads (copies of real pads inside a bin)
with gst_element_add_ghost_pad() and gst_element_remove_ghost_pad().
A pad of an element can be retrieved by name with gst_element_get_pad().
A GList of all pads can be retrieved with gst_element_get_pad_list().
</para>

<para>
Elements can be linked through their pads.
If the link is straightforward, use the gst_element_link() 
convenience function to link two elements, or gst_element_link_many() 
for more elements in a row.
Use gst_element_link_filtered() to link two elements constrained by
a specified set of #GstCaps.
For finer control, use gst_element_link_pads() and 
gst_element_link_pads_filtered() to specify the pads to link on 
each element by name.
</para>

<para>
Each element has a state (see #GstState).  You can get and set the state
of an element with gst_element_get_state() and gst_element_set_state().  
You can wait for an element to change it's state with gst_element_wait_state_change().
To get a string representation of a #GstState, use 
gst_element_state_get_name().
</para>

<para>
You can get and set a #GstClock on an element using gst_element_get_clock()
and gst_element_set_clock().  You can wait for the clock to reach a given
#GstClockTime using gst_element_clock_wait().
</para>

<!-- ##### SECTION See_Also ##### -->
<para>
#GstElementFactory, #GstPad
</para>

<!-- basic object functions -->

<!-- ##### SECTION Stability_Level ##### -->


<!-- ##### STRUCT GstElement ##### -->
<para>

</para>

@state_lock: 
@state_cond: 
@current_state: 
@pending_state: 
@final_state: 
@state_error: 
@no_preroll: 
@bus: 
@clock: 
@base_time: 
@numpads: 
@pads: 
@numsrcpads: 
@srcpads: 
@numsinkpads: 
@sinkpads: 
@pads_cookie: 

<!-- ##### SIGNAL GstElement::no-more-pads ##### -->
<para>

</para>

@gstelement: the object which received the signal.

<!-- ##### SIGNAL GstElement::pad-added ##### -->
<para>

</para>

@gstelement: the object which received the signal.
@arg1: 

<!-- ##### SIGNAL GstElement::pad-removed ##### -->
<para>

</para>

@gstelement: the object which received the signal.
@arg1: 

<!-- ##### SIGNAL GstElement::state-changed ##### -->
<para>

</para>

@gstelement: the object which received the signal.
@arg1: 
@arg2: 

<!-- ##### STRUCT GstElementClass ##### -->
<para>

</para>

@parent_class: 
@details: 
@elementfactory: 
@padtemplates: 
@numpadtemplates: 
@pad_templ_cookie: 
@request_new_pad: 
@release_pad: 
@get_state: 
@change_state: 
@set_bus: 
@get_clock: 
@set_clock: 
@get_index: 
@set_index: 
@send_event: 
@get_query_types: 
@query: 

<!-- ##### ENUM GstElementFlags ##### -->
<para>
This enum defines the standard flags that an element may have.
</para>

@GST_ELEMENT_LOCKED_STATE: 
@GST_ELEMENT_IS_SINK: 
@GST_ELEMENT_UNPARENTING: 
@GST_ELEMENT_FLAG_LAST: 

<!-- ##### ENUM GstStateChange ##### -->
<para>

</para>

@GST_STATE_CHANGE_NULL_TO_READY: 
@GST_STATE_CHANGE_READY_TO_PAUSED: 
@GST_STATE_CHANGE_PAUSED_TO_PLAYING: 
@GST_STATE_CHANGE_PLAYING_TO_PAUSED: 
@GST_STATE_CHANGE_PAUSED_TO_READY: 
@GST_STATE_CHANGE_READY_TO_NULL: 

<!-- ##### MACRO GST_STATE ##### -->
<para>
This macro returns the current state of the element.
</para>

@obj: Element to return state for.


<!-- ##### MACRO GST_STATE_PENDING ##### -->
<para>
This macro returns the currently pending state of the element.
</para>

@obj: Element to return the pending state for.


<!-- ##### MACRO GST_STATE_CHANGE ##### -->
<para>

</para>

@obj: 


<!-- ##### MACRO GST_STATE_BROADCAST ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_ERROR ##### -->
<para>

</para>

@obj: 


<!-- ##### MACRO GST_STATE_FINAL ##### -->
<para>

</para>

@obj: 


<!-- ##### MACRO GST_STATE_GET_COND ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_GET_LOCK ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_LOCK ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_NO_PREROLL ##### -->
<para>

</para>

@obj: 


<!-- ##### MACRO GST_STATE_SIGNAL ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_TIMED_WAIT ##### -->
<para>

</para>

@elem: 
@timeval: 


<!-- ##### MACRO GST_STATE_TRYLOCK ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_UNLOCK ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_STATE_WAIT ##### -->
<para>

</para>

@elem: 


<!-- ##### MACRO GST_ELEMENT_NAME ##### -->
<para>
Gets the name of this element.  Used in the core.  Not ABI-compatible.
</para>

@obj: A #GstElement to query


<!-- ##### MACRO GST_ELEMENT_PARENT ##### -->
<para>
Get the parent object of this element.
</para>

@obj: a #GstElement to query


<!-- ##### MACRO GST_ELEMENT_CLOCK ##### -->
<para>
Get the clock of this element
</para>

@obj: a #GstElement to query


<!-- ##### MACRO GST_ELEMENT_PADS ##### -->
<para>
Get the pads of this elements.
</para>

@obj: a #GstElement to query


<!-- ##### MACRO GST_ELEMENT_ERROR ##### -->
<para>

</para>

@el: 
@domain: 
@code: 
@text: 
@debug: 
<!-- # Unused Parameters # -->
@message: 


<!-- ##### MACRO GST_ELEMENT_BUS ##### -->
<para>

</para>

@obj: 


<!-- ##### MACRO GST_ELEMENT_WARNING ##### -->
<para>

</para>

@el: 
@domain: 
@code: 
@text: 
@debug: 


<!-- ##### MACRO GST_ELEMENT_IS_LOCKED_STATE ##### -->
<para>

</para>

@obj: 


<!-- ##### FUNCTION gst_element_abort_preroll ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_abort_state ##### -->
<para>

</para>

@element: 


<!-- ##### FUNCTION gst_element_add_pad ##### -->
<para>

</para>

@element: 
@pad: 
@Returns: 


<!-- ##### FUNCTION gst_element_class_add_pad_template ##### -->
<para>

</para>

@klass: 
@templ: 


<!-- ##### FUNCTION gst_element_class_get_pad_template ##### -->
<para>

</para>

@element_class: 
@name: 
@Returns: 


<!-- ##### FUNCTION gst_element_class_get_pad_template_list ##### -->
<para>

</para>

@element_class: 
@Returns: 


<!-- ##### FUNCTION gst_element_class_install_std_props ##### -->
<para>

</para>

@klass: 
@first_name: 
@Varargs: 


<!-- ##### FUNCTION gst_element_class_set_details ##### -->
<para>

</para>

@klass: 
@details: 


<!-- ##### FUNCTION gst_element_commit_state ##### -->
<para>

</para>

@element: 


<!-- ##### FUNCTION gst_element_create_all_pads ##### -->
<para>

</para>

@element: 


<!-- ##### FUNCTION gst_element_factory_can_sink_caps ##### -->
<para>

</para>

@factory: 
@caps: 
@Returns: 


<!-- ##### FUNCTION gst_element_factory_can_src_caps ##### -->
<para>

</para>

@factory: 
@caps: 
@Returns: 


<!-- ##### FUNCTION gst_element_factory_get_static_pad_templates ##### -->
<para>

</para>

@factory: 
@Returns: 


<!-- ##### FUNCTION gst_element_finish_preroll ##### -->
<para>

</para>

@element: 
@pad: 
@Returns: 


<!-- ##### FUNCTION gst_element_found_tags ##### -->
<para>

</para>

@element: 
@list: 


<!-- ##### FUNCTION gst_element_found_tags_for_pad ##### -->
<para>

</para>

@element: 
@pad: 
@list: 


<!-- ##### FUNCTION gst_element_get_base_time ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_bus ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_clock ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_compatible_pad ##### -->
<para>

</para>

@element: 
@pad: 
@caps: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_compatible_pad_template ##### -->
<para>

</para>

@element: 
@compattempl: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_factory ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_index ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### MACRO gst_element_get_name ##### -->
<para>
Gets the name of the element.
</para>

@elem: 
@Returns: the name of the element.


<!-- link -->


<!-- ##### FUNCTION gst_element_get_pad ##### -->
<para>

</para>

@element: 
@name: 
@Returns: GList of #GstPads


<!-- ##### MACRO gst_element_get_parent ##### -->
<para>
Gets the parent of an element.
</para>

@elem: a #GstElement to get the parent of.
@Returns: the #GstObject parent of the element.


<!-- ##### FUNCTION gst_element_get_query_types ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_request_pad ##### -->
<para>

</para>

@element: 
@name: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_state ##### -->
<para>

</para>

@element: 
@state: 
@pending: 
@timeout: 
@Returns: 


<!-- ##### FUNCTION gst_element_get_static_pad ##### -->
<para>

</para>

@element: 
@name: 
@Returns: 


<!-- ##### FUNCTION gst_element_is_indexable ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_is_locked_state ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_iterate_pads ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_iterate_sink_pads ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_iterate_src_pads ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_link ##### -->
<para>

</para>

@src: 
@dest: 
@Returns: 


<!-- ##### FUNCTION gst_element_link_many ##### -->
<para>

</para>

@element_1: 
@element_2: 
@Varargs: 
@Returns: 


<!-- ##### FUNCTION gst_element_link_filtered ##### -->
<para>

</para>

@src: 
@dest: 
@filter: 
@Returns: 


<!-- ##### FUNCTION gst_element_link_pads ##### -->
<para>

</para>

@src: 
@srcpadname: 
@dest: 
@destpadname: 
@Returns: 


<!-- ##### FUNCTION gst_element_link_pads_filtered ##### -->
<para>

</para>

@src: 
@srcpadname: 
@dest: 
@destpadname: 
@filter: 
@Returns: 


<!-- ##### FUNCTION gst_element_lost_state ##### -->
<para>

</para>

@element: 


<!-- ##### FUNCTION gst_element_message_full ##### -->
<para>

</para>

@element: 
@type: 
@domain: 
@code: 
@text: 
@debug: 
@file: 
@function: 
@line: 


<!-- ##### FUNCTION gst_element_no_more_pads ##### -->
<para>

</para>

@element: 


<!-- ##### FUNCTION gst_element_post_message ##### -->
<para>

</para>

@element: 
@message: 
@Returns: 


<!-- ##### FUNCTION gst_element_provides_clock ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_query ##### -->
<para>

</para>

@element: 
@query: 
@Returns: 
<!-- # Unused Parameters # -->
@type: 
@format: 
@value: 


<!-- ##### FUNCTION gst_element_query_convert ##### -->
<para>

</para>

@element: 
@src_format: 
@src_val: 
@dest_fmt: 
@dest_val: 
@Returns: 


<!-- ##### FUNCTION gst_element_query_position ##### -->
<para>

</para>

@element: 
@format: 
@cur: 
@end: 
@Returns: 


<!-- ##### FUNCTION gst_element_release_request_pad ##### -->
<para>

</para>

@element: 
@pad: 


<!-- ##### FUNCTION gst_element_remove_pad ##### -->
<para>

</para>

@element: 
@pad: 
@Returns: 


<!-- ##### FUNCTION gst_element_requires_clock ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_seek ##### -->
<para>

</para>

@element: 
@rate: 
@format: 
@flags: 
@cur_type: 
@cur: 
@stop_type: 
@stop: 
@Returns: 
<!-- # Unused Parameters # -->
@seek_type: 
@offset: 


<!-- ##### FUNCTION gst_element_send_event ##### -->
<para>

</para>

@element: 
@event: 
@Returns: 


<!-- ##### FUNCTION gst_element_set_base_time ##### -->
<para>

</para>

@element: 
@time: 


<!-- ##### FUNCTION gst_element_set_bus ##### -->
<para>

</para>

@element: 
@bus: 


<!-- ##### FUNCTION gst_element_set_clock ##### -->
<para>

</para>

@element: 
@clock: 


<!-- ##### FUNCTION gst_element_set_index ##### -->
<para>

</para>

@element: 
@index: 


<!-- ##### FUNCTION gst_element_set_locked_state ##### -->
<para>

</para>

@element: 
@locked_state: 
@Returns: 


<!-- ##### MACRO gst_element_set_name ##### -->
<para>
Sets the name of the element, getting rid of the old name if there was one.
</para>

@elem: a #GstElement to set the name of.
@name: the new name of the element.


<!-- ##### MACRO gst_element_set_parent ##### -->
<para>
Sets the parent of an element.
</para>

@elem: a #GstElement to set the parent of.
@parent:  the new #GstObject parent of the object.


<!-- ##### FUNCTION gst_element_set_state ##### -->
<para>

</para>

@element: 
@state: 
@Returns: 


<!-- ##### FUNCTION gst_element_state_get_name ##### -->
<para>

</para>

@state: 
@Returns: 


<!-- ##### FUNCTION gst_element_sync_state_with_parent ##### -->
<para>

</para>

@element: 
@Returns: 


<!-- ##### FUNCTION gst_element_unlink ##### -->
<para>

</para>

@src: 
@dest: 


<!-- ##### FUNCTION gst_element_unlink_many ##### -->
<para>

</para>

@element_1: 
@element_2: 
@Varargs: 


<!-- ##### FUNCTION gst_element_unlink_pads ##### -->
<para>

</para>

@src: 
@srcpadname: 
@dest: 
@destpadname: 


<!-- pad manipulation -->