mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
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499 lines
8 KiB
Plaintext
499 lines
8 KiB
Plaintext
<!-- ##### SECTION Title ##### -->
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GstElement
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<!-- ##### SECTION Short_Description ##### -->
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Base class for all pipeline elements
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<!-- ##### SECTION Long_Description ##### -->
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<para>
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GstElement is the base class needed to construct an element that can be
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used in a GST pipeline. As such, it is not a functional entity, and
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cannot do anything when placed in a pipeline.
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</para>
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<para>
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All GstElements have a list containing the #GstPad structure for all their
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inputs and outputs. These can be added with gst_element_add_pad() or
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gst_element_add_ghost_pad(), and retrieved by name with
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gst_element_get_pad(), or in a list form by gst_element_get_pad_list().
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</para>
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<para>
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gst_element_connect() is a convenience function provided to make it
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simpler to connect pads of two elements together.
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</para>
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<!-- ##### SECTION See_Also ##### -->
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<para>
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</para>
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<!-- ##### ENUM GstElementState ##### -->
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<para>
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This enum defines the standard states an element may be in. You will normally
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use gst_element_set_state() to change the state of an element.
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<informaltable pgwide=1 frame="none" role="enum">
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<tgroup cols="2"><colspec colwidth="2*"><colspec colwidth="8*">
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<tbody>
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<row>
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<entry>GST_STATE_NONE_PENDING</entry>
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<entry>The element is in the desired state.</entry>
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</row>
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<row>
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<entry>GST_STATE_NULL</entry>
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<entry>Reset the state of an element.</entry>
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</row>
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<row>
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<entry>GST_STATE_READY</entry>
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<entry>will make the element ready to start processing data. some
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elements might have a non trivial way to initialize themselves.
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</entry>
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</row>
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<row>
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<entry>GST_STATE_PLAYING</entry>
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<entry>means there really is data flowing through the graph.
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</entry>
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</row>
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<row>
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<entry>GST_STATE_PAUSED</entry>
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<entry>means there really is data flowing
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temporary stops the data flow.
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</entry>
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</row>
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</tbody></tgroup></informaltable>
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</para>
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@GST_STATE_NONE_PENDING:
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@GST_STATE_NULL:
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@GST_STATE_READY:
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@GST_STATE_PLAYING:
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@GST_STATE_PAUSED:
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<!-- ##### ENUM GstElementStateReturn ##### -->
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<para>
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This enum defines the standard return values that an element
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can return after a state change.
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<informaltable pgwide=1 frame="none" role="enum">
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<tgroup cols="2"><colspec colwidth="2*"><colspec colwidth="8*">
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<tbody>
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<row>
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<entry>GST_STATE_FAILURE</entry>
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<entry>the element could not perform the state change</entry>
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</row>
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<row>
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<entry>GST_STATE_SUCCESS</entry>
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<entry>the element successfully changed its state</entry>
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</row>
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<row>
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<entry>GST_STATE_ASYNC</entry>
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<entry>the element will asynchronously change its state as soon as possible
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</entry>
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</row>
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</tbody></tgroup></informaltable>
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</para>
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@GST_STATE_FAILURE:
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@GST_STATE_SUCCESS:
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@GST_STATE_ASYNC:
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<!-- ##### MACRO GST_STATE ##### -->
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<para>
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This macro returns the entire state of the element.
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</para>
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@obj: Element to return state for.
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<!-- ##### MACRO GST_STATE_PENDING ##### -->
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<para>
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This macro returns the currently pending state of the element.
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</para>
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@obj: Element to return the pending state for.
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<!-- ##### ENUM GstElementFlags ##### -->
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<para>
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This enum defines the standard flags that an element
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may have.
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<informaltable pgwide=1 frame="none" role="enum">
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<tgroup cols="2"><colspec colwidth="2*"><colspec colwidth="8*">
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<tbody>
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<row>
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<entry>GST_ELEMENT_MULTI_IN</entry>
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<entry>the element has multiple input pads</entry>
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</row>
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</tbody></tgroup></informaltable>
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</para>
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@GST_ELEMENT_MULTI_IN:
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@GST_ELEMENT_THREAD_SUGGESTED:
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@GST_ELEMENT_NO_SEEK:
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<!-- ##### MACRO GST_ELEMENT_IS_MULTI_IN ##### -->
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<para>
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Query whether this object has multiple input pads.
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</para>
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@obj: Element to query for multiple input pads.
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<!-- ##### MACRO GST_ELEMENT_IS_THREAD_SUGGESTED ##### -->
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<para>
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</para>
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@obj:
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<!-- ##### STRUCT GstElement ##### -->
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<para>
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</para>
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<!-- ##### STRUCT GstElementDetails ##### -->
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<para>
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This struct is used to define public information about the element. It
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describes the element, mostly for the benefit of editors.
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</para>
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@longname:
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@class:
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@description:
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@version:
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@author:
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@copyright:
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<!-- ##### STRUCT GstElementFactory ##### -->
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<para>
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This factory is used when registering the element, and contains the name
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of the element, the GtkType value for it, as well as a pointer to the
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GstElementDetails struct for the element.
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</para>
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@name:
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@type:
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@details:
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@src_types:
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@sink_types:
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<!-- ##### USER_FUNCTION GstElementLoopFunction ##### -->
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<para>
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This function type is used to specify a loop function for the element. It
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is passed the element in question, and is expect to return only in error
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circumstances.
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</para>
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@element: The element in question.
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<!-- ##### FUNCTION gst_element_new ##### -->
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<para>
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</para>
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@Returns:
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<!-- ##### FUNCTION gst_element_set_loop_function ##### -->
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<para>
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</para>
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@element:
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@loop:
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<!-- ##### FUNCTION gst_element_set_name ##### -->
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<para>
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</para>
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@element:
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@name:
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<!-- ##### FUNCTION gst_element_get_name ##### -->
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<para>
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</para>
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@element:
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@Returns:
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<!-- ##### FUNCTION gst_element_set_manager ##### -->
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<para>
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</para>
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@element:
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@manager:
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<!-- ##### FUNCTION gst_element_get_manager ##### -->
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<para>
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</para>
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@element:
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@Returns:
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<!-- ##### FUNCTION gst_element_add_pad ##### -->
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<para>
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</para>
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@element:
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@pad:
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<!-- ##### FUNCTION gst_element_add_ghost_pad ##### -->
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<para>
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</para>
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@element:
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@pad:
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<!-- ##### FUNCTION gst_element_get_pad ##### -->
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<para>
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</para>
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@element:
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@name:
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@Returns: GList of pads
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<!-- ##### FUNCTION gst_element_get_pad_list ##### -->
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<para>
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</para>
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@element:
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@Returns:
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<!-- ##### FUNCTION gst_element_connect ##### -->
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<para>
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</para>
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@src:
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@srcpadname:
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@dest:
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@destpadname:
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<!-- ##### FUNCTION gst_element_set_state ##### -->
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<para>
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</para>
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@element:
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@state:
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@Returns:
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<!-- ##### FUNCTION gst_element_error ##### -->
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<para>
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</para>
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@element:
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@error:
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<!-- ##### FUNCTION gst_element_get_factory ##### -->
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<para>
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</para>
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@element:
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@Returns:
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<!-- ##### MACRO gst_element_destroy ##### -->
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<para>
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</para>
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@element: the element to destroy
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<!-- ##### FUNCTION gst_element_save_thyself ##### -->
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<para>
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</para>
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@element:
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@parent:
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@Returns:
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<!-- ##### FUNCTION gst_element_load_thyself ##### -->
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<para>
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</para>
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@parent:
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@elements:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_new ##### -->
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<para>
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</para>
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@name:
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@type:
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@details:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_register ##### -->
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<para>
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</para>
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@elementfactory:
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<!-- ##### FUNCTION gst_elementfactory_add_sink ##### -->
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<para>
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</para>
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@elementfactory:
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@id:
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<!-- ##### FUNCTION gst_elementfactory_add_src ##### -->
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<para>
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</para>
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@elementfactory:
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@id:
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<!-- ##### FUNCTION gst_elementfactory_find ##### -->
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<para>
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</para>
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@name:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_get_list ##### -->
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<para>
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</para>
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_create ##### -->
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<para>
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</para>
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@factory:
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@name:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_make ##### -->
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<para>
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</para>
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@factoryname:
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@name:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_save_thyself ##### -->
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<para>
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</para>
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@factory:
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@parent:
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@Returns:
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<!-- ##### FUNCTION gst_elementfactory_load_thyself ##### -->
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<para>
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</para>
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@parent:
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@Returns:
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<!-- ##### FUNCTION gst_element_loopfunc_wrapper ##### -->
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<para>
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</para>
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@argc:
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@argv:
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@Returns:
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<!-- ##### SIGNAL GstElement::state-change ##### -->
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<para>
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Is trigered whenever the state of an element changes
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</para>
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@gstelement: the object which received the signal.
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@arg1: the new state of the object
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<!-- ##### SIGNAL GstElement::new-pad ##### -->
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<para>
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Is trigered whenever a new pad is added to an element
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</para>
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@gstelement: the object which received the signal.
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@arg1: the new pad that was added
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<!-- ##### SIGNAL GstElement::new-ghost-pad ##### -->
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<para>
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Is trigered whenever a new ghost pad is added to an element
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</para>
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@gstelement: the object which received the signal.
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@arg1: the new ghost pad that was added
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<!-- ##### SIGNAL GstElement::error ##### -->
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<para>
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Is trigered whenever an error occured
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</para>
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@gstelement: the object which received the signal.
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@arg1: the error message
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