gstreamer/docs/gst/tmpl/gst.sgml

190 lines
3.8 KiB
Text
Raw Normal View History

<!-- ##### SECTION Title ##### -->
Gstreamer
<!-- ##### SECTION Short_Description ##### -->
Media library supporting arbitrary formats and filter graphs.
<!-- ##### SECTION Long_Description ##### -->
<para>
GStreamer is a framework for constructing graphs of various filters
(termed elements here) that will handle streaming media. Any discreet
(packetizable) media type is supported, with provisions for automatically
determining source type. Formatting/framing information is provided with
a powerful negotiation framework. Plugins are heavily used to provide for
all elements, allowing one to construct plugins outside of the GST
library, even released binary-only if license require (please don't).
</para>
<para>
GStreamer borrows heavily from both the <ulink
url="http://www.cse.ogi.edu/sysl/">OGI media pipeline</ulink> and
Microsoft's DirectShow, hopefully taking the best of both and leaving the
cruft behind. Its interface is still very fluid and thus can be changed
to increase the sanity/noise ratio.
</para>
<para>
The <application>GStreamer</application> library should be initialized with gst_init() before
it can be used. You should pass a pointer to the main argc and argv variables so that GStreamer can
process its own command line options, as shown in the following example.
<programlisting>
int
main (int argc, char *argv[])
{
/* initialize the GStreamer library */
gst_init (&amp;argc, &amp;argv);
...
}
</programlisting>
</para>
<para>
It's allowed to pass two NULL pointers to gst_init() in case you don't want to pass the command
line args to GStreamer.
</para>
<para>
You can also use a popt table to initialize your own parameters as shown in the next code
fragment:
<programlisting>
static gboolean stats = FALSE;
...
int
main (int argc, char *argv[])
{
struct poptOption options[] = {
{ "stats", 's', POPT_ARG_NONE|POPT_ARGFLAG_STRIP, &amp;stats, 0,
"Show pad stats", NULL},
POPT_TABLEEND
};
/* initialize the GStreamer library */
gst_init_with_popt_table (&amp;argc, &amp;argv, options);
...
}
</programlisting>
</para>
<para>
Use gst_version() to query the library version at runtime or use the GST_VERSION_* macros
to find the version at compile time.
</para>
<para>
gst_main() and gst_main_quit() enter and exit the main loop. GStreamer doesn't currently require
you to us a mainloop but can intergrate with it without problems.
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
Check out both <ulink url="http://www.cse.ogi.edu/sysl/">OGI's
pipeline</ulink> and Microsoft's DirectShow for some background.
</para>
<!-- ##### FUNCTION gst_init ##### -->
<para>
</para>
@argc:
@argv:
<!-- ##### FUNCTION gst_init_with_popt_table ##### -->
<para>
</para>
@argc:
@argv:
@popt_options:
<!-- # Unused Parameters # -->
@Returns:
<!-- ##### FUNCTION gst_init_check ##### -->
<para>
</para>
@argc:
@argv:
@Returns:
<!-- ##### FUNCTION gst_init_get_popt_table ##### -->
<para>
</para>
@Returns:
<!-- ##### FUNCTION gst_version ##### -->
<para>
</para>
@major:
@minor:
@micro:
<!-- ##### FUNCTION gst_main ##### -->
<para>
</para>
<!-- ##### FUNCTION gst_main_quit ##### -->
<para>
</para>
<!-- ##### FUNCTION gst_has_threads ##### -->
<para>
</para>
@Returns:
<!-- ##### FUNCTION gst_use_threads ##### -->
<para>
</para>
@use_threads:
<!-- ##### VARIABLE g_log_domain_gstreamer ##### -->
<para>
The variable that holds the GStreamer log domain
</para>
<!-- ##### MACRO GST_VERSION_MAJOR ##### -->
<para>
The major version of GStreamer at compile time
</para>
<!-- ##### MACRO GST_VERSION_MINOR ##### -->
<para>
The minor version of GStreamer at compile time
</para>
<!-- ##### MACRO GST_VERSION_MICRO ##### -->
<para>
The micro version of GStreamer at compile time
</para>