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><A
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>12.2. GstElement properties</A
></H1
><P
>
A <CODE
CLASS="classname"
>GstElement</CODE
> can have several properties
which are implemented using standard <CODE
CLASS="classname"
>GObject</CODE
>
properties. The usual <CODE
CLASS="classname"
>GObject</CODE
> methods to query,
set and get property values and <CODE
CLASS="classname"
>GParamSpecs</CODE
>
are therefore supported.
</P
><P
>
Every <CODE
CLASS="classname"
>GstElement</CODE
> inherits at least
one property of its parent <CODE
CLASS="classname"
>GstObject</CODE
>:
the "name" property. This is the name you provide to the
functions <CODE
CLASS="function"
>gst_element_factory_make</CODE
> or
<CODE
CLASS="function"
>gst_element_factory_create</CODE
>. You can get and set
this property using the functions
<CODE
CLASS="function"
>gst_object_set_name</CODE
>
and <CODE
CLASS="function"
>gst_object_get_name</CODE
> or use the
<CODE
CLASS="classname"
>GObject</CODE
> property mechanism as shown below.
</P
><PRE
CLASS="programlisting"
> GstElement *element;
GValue value = { 0, }; /* initialize the GValue for g_object_get() */
element = gst_element_factory_make ("mad", "decoder");
g_object_set (G_OBJECT (element), "name", "mydecoder", NULL);
...
g_value_init (&value, G_TYPE_STRING);
g_object_get_property (G_OBJECT (element), "name", &value);
...
</PRE
><P
>
Most plugins provide additional properties to provide more information
about their configuration or to configure the element.
<B
CLASS="command"
>gst-inspect</B
> is a useful tool to query the properties
of a particular element, it will also use property introspection to give
a short explanation about the function of the property and about the
parameter types and ranges it supports.
</P
><P
>
For more information about <CODE
CLASS="classname"
>GObject</CODE
>
properties we recommend you read the <A
HREF="http://developer.gnome.org/doc/API/2.0/gobject/index.html"
TARGET="_top"
>GObject manual</A
> and an introduction to <A
HREF="http://le-hacker.org/papers/gobject/index.html"
TARGET="_top"
> The Glib Object system</A
>.
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