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>Chapter 13. Interfaces</H1
><P
> In <A
HREF="section-elements-properties.html"
>Section 5.3</A
>, you have learned how
to use <CODE
CLASS="classname"
>GObject</CODE
> properties as a simple way to do
interaction between applications and elements. This method suffices for
the simple'n'straight settings, but fails for anything more complicated
than a getter and setter. For the more complicated use cases, <SPAN
CLASS="application"
>GStreamer</SPAN
>
uses interfaces based on the GObject <A
HREF="http://library.gnome.org/devel/gobject/stable/gtype-non-instantiable-classed.html"
TARGET="_top"
><CODE
CLASS="classname"
>GTypeInterface</CODE
></A
>
type.
</P
><P
> Most of the interfaces handled here will not contain any example code.
See the API references for details. Here, we will just describe the
scope and purpose of each interface.
</P
><DIV
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><H1
CLASS="sect1"
><A
NAME="section-interfaces-uri"
>13.1. The URI interface</A
></H1
><P
> In all examples so far, we have only supported local files through the
<SPAN
CLASS="QUOTE"
>"filesrc"</SPAN
> element. <SPAN
CLASS="application"
>GStreamer</SPAN
>, obviously, supports many
more location sources. However, we don't want applications to need to
know any particular element implementation details, such as element
names for particular network source types and so on. Therefore, there
is a URI interface, which can be used to get the source element that
supports a particular URI type. There is no strict rule for URI naming,
but in general we follow naming conventions that others use, too. For
example, assuming you have the correct plugins installed, <SPAN
CLASS="application"
>GStreamer</SPAN
>
supports <SPAN
CLASS="QUOTE"
>"file:///<path>/<file>"</SPAN
>,
<SPAN
CLASS="QUOTE"
>"http://<host>/<path>/<file>"</SPAN
>,
<SPAN
CLASS="QUOTE"
>"mms://<host>/<path>/<file>"</SPAN
>, and so on.
</P
><P
> In order to get the source or sink element supporting a particular URI,
use <CODE
CLASS="function"
>gst_element_make_from_uri ()</CODE
>, with the URI
type being either <CODE
CLASS="classname"
>GST_URI_SRC</CODE
> for a source
element, or <CODE
CLASS="classname"
>GST_URI_SINK</CODE
> for a sink element.
</P
><P
> You can convert filenames to and from URIs using GLib's
<CODE
CLASS="function"
>g_filename_to_uri ()</CODE
> and
<CODE
CLASS="function"
>g_uri_to_filename ()</CODE
>.
</P
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