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<chapter id="chapter-intgration">
<title>Integration</title>
<para>
&GStreamer; tries to integrate closely with operating systems (such
as Linux and UNIX-like operating systems, OS X or Windows) and desktop
environments (such as GNOME or KDE). In this chapter, we'll mention
some specific techniques to integrate your application with your
operating system or desktop environment of choice.
</para>
<sect1 id="section-integration-nix">
<title>Linux and UNIX-like operating systems</title>
<para>
&GStreamer; provides a basic set of elements that are useful when
integrating with Linux or a UNIX-like operating system.
</para>
<itemizedlist>
<listitem>
<para>
For audio input and output, &GStreamer; provides input and
output elements for several audio subsystems. Amongst others,
&GStreamer; includes elements for ALSA (alsasrc, alsamixer,
alsasink), OSS (osssrc, ossmixer, osssink) and Sun audio
(sunaudiosrc, sunaudiomixer, sunaudiosink).
</para>
</listitem>
<listitem>
<para>
For video input, &GStreamer; contains source elements for
Video4linux (v4lsrc, v4lmjpegsrc, v4lelement and v4lmjpegisnk)
and Video4linux2 (v4l2src, v4l2element).
</para>
</listitem>
<listitem>
<para>
For video output, &GStreamer; provides elements for output
to X-windows (ximagesink), Xv-windows (xvimagesink; for
hardware-accelerated video), direct-framebuffer (dfbimagesink)
and openGL image contexts (glsink).
</para>
</listitem>
</itemizedlist>
</sect1>
<sect1 id="section-integration-gnome">
<title>GNOME desktop</title>
<para>
&GStreamer; has been the media backend of the <ulink type="http"
url="http://www.gnome.org/">GNOME</ulink> desktop since GNOME-2.2
onwards. Nowadays, a whole bunch of GNOME applications make use of
&GStreamer; for media-processing, including (but not limited to)
<ulink type="http" url="http://www.rhythmbox.org/">Rhythmbox</ulink>,
<ulink type="http" url="http://www.hadess.net/totem.php3">Totem</ulink>
and <ulink type="http"
url="http://www.burtonini.com/blog/computers/sound-juicer">Sound
Juicer</ulink>.
</para>
<para>
Most of these GNOME applications make use of some specific techniques
to integrate as closely as possible with the GNOME desktop:
</para>
<itemizedlist>
<listitem>
<para>
GNOME applications call <function>gnome_program_init ()</function>
to parse command-line options and initialize the necessary gnome
modules. &GStreamer; applications would normally call
<function>gst_init ()</function> to do the same for GStreamer.
This would mean that only one of the two can parse command-line
options. To work around this issue, &GStreamer; can provide a
GLib <classname>GOptionGroup</classname> which can be passed to
<function>gnome_program_init ()</function>. The following
example requires Gnome-2.14 or newer (previous libgnome versions
do not support command line parsing via GOption yet but use the
now deprecated popt)
</para>
<programlisting><!-- example-begin gnome.c a -->
#include <gnome.h>
#include <gst/gst.h>
static gchar **cmd_filenames = NULL;
static GOptionEntries cmd_options[] = {
/* here you can add command line options for your application. Check
* the GOption section in the GLib API reference for a more elaborate
* example of how to add your own command line options here */
/* at the end we have a special option that collects all remaining
* command line arguments (like filenames) for us. If you don'
* need this, you can safely remove it */
{ G_OPTION_REMAINING, 0, 0, G_OPTION_ARG_FILENAME_ARRAY, &cmd_filenames,
"Special option that collects any remaining arguments for us" },
/* mark the end of the options array with a NULL option */
{ NULL, }
};
/* this should usually be defined in your config.h */
#define VERSION "0.0.1"
gint
main (gint argc, gchar **argv)
{
GOptionContext *context;
GOptionGroup *gstreamer_group;
GnomeProgram *program;
context = g_option_context_new ("gnome-demo-app");
/* get command line options from GStreamer and add them to the group */
gstreamer_group = gst_init_get_option_group ();
g_option_context_add_group (context, gstreamer_group);
/* add our own options. If you are using gettext for translation of your
* strings, use GETTEXT_PACKAGE here instead of NULL */
g_option_context_add_main_entries (context, cmd_options, NULL);
program = gnome_program_init ("gnome-demo-app", VERSION
LIBGNOMEUI_MODULE, argc, argv,
GNOME_PARAM_HUMAN_READABLE_NAME, "Gnome Demo",
GNOME_PARAM_GOPTION_CONTEXT, context,
NULL);
/* any filenames we got passed on the command line? parse them! */
if (cmd_filenames != NULL) {
guint i, num;
num = g_strv_length (cmd_filenames);
for (i = 0; i < num; ++i) {
/* do something with the filename ... */
g_print ("Adding to play queue: %s\n", cmd_filenames[i]);
}
g_strfreev (cmd_filenames);
cmd_filenames = NULL;
}
<!-- example-end gnome.c a -->
[..]<!-- example-begin gnome.c b --><!--
return 0;
--><!-- example-end gnome.c b -->
<!-- example-begin gnome.c c -->
}
<!-- example-end gnome.c c --></programlisting>
</listitem>
<listitem>
<para>
GNOME stores the default video and audio sources and sinks in GConf.
&GStreamer; provides a number of elements that create audio and
video sources and sinks directly based on those GConf settings.
Those elements are: gconfaudiosink, gconfvideosink, gconfaudiosrc
and gconfvideosrc. You can create them with
<function>gst_element_factory_make ()</function> and use them
directly just like you would use any other source or sink element.
All GNOME applications are recommended to use those elements.
</para>
</listitem>
<listitem>
<para>
&GStreamer; provides data input/output elements for use with the
GNOME-VFS system. These elements are called <quote>gnomevfssrc</quote>
and <quote>gnomevfssink</quote>.
</para>
</listitem>
</itemizedlist>
</sect1>
<sect1 id="section-integration-kde">
<title>KDE desktop</title>
<para>
&GStreamer; has been proposed for inclusion in KDE-4.0. Currently,
&GStreamer; is included as an optional component, and it's used by
several KDE applications, including <ulink type="http"
url="http://amarok.kde.org/">AmaroK</ulink>, <ulink type="http"
url="http://developer.kde.org/~wheeler/juk.html">JuK</ulink>,
<ulink type="http"
url="http://www.xs4all.nl/~jjvrieze/kmplayer.html">KMPlayer</ulink> and
<ulink type="http"
url="http://kaffeine.sourceforge.net/">Kaffeine</ulink>.
</para>
<para>
Although not yet as complete as the GNOME integration bits, there
are already some KDE integration specifics available. This list will
probably grow as &GStreamer; starts to be used in KDE-4.0:
</para>
<itemizedlist>
<listitem>
<para>
AmaroK contains a kiosrc element, which is a source element that
integrates with the KDE VFS subsystem KIO.
</para>
</listitem>
</itemizedlist>
</sect1>
<sect1 id="section-integration-osx">
<title>OS X</title>
<para>
&GStreamer; provides native video and audio output elements for OS X.
It builds using the standard development tools for OS X.
</para>
</sect1>
<sect1 id="section-integration-win32">
<title>Windows</title>
<para>
&GStreamer; builds using Microsoft Visual C .NET 2003 and using Cygwin.
</para>
</sect1>
</chapter>
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