gstreamer/docs/gst/tmpl/gstpadtemplate.sgml
Andy Wingo ad1970eae2 tools/gst-typefind.c: Update, add copyright block.
Original commit message from CVS:
2005-07-15  Andy Wingo  <wingo@pobox.com>

* tools/gst-typefind.c: Update, add copyright block.

* gst/base/gstbasesrc.c (gst_base_src_default_negotiate):
Normalize and truncate caps before fixation.

* gst/gstcaps.h:
* gst/gstcaps.c (gst_caps_truncate): New function, destructively
discards all but the first structure from its argument.
2005-07-15 11:04:18 +00:00

193 lines
3.9 KiB
Text

<!-- ##### SECTION Title ##### -->
GstPadTemplate
<!-- ##### SECTION Short_Description ##### -->
Describe the media type of a pad.
<!-- ##### SECTION Long_Description ##### -->
<para>
Padtemplates describe the possible media types a pad or an elementfactory can
handle.
</para>
<para>
Pad and PadTemplates have #GstCaps attached to it to describe the media type they
are capable of dealing with. gst_pad_template_get_caps() is used to get the
caps of a padtemplate. It's not possible to modify the caps of a padtemplate after
creation.
</para>
<para>
Padtemplates can be created with gst_pad_template_new() or with the convenient
GST_PAD_TEMPLATE_FACTORY() macro. A padtemplate can be used to create a pad or
to add to an elementfactory.
</para>
<para>
The following code example shows the code to create a pad from a padtemplate.
<example>
<title>Create a pad from a padtemplate</title>
<programlisting>
GstStaticPadTemplate my_template =
GST_STATIC_PAD_TEMPLATE (
"sink", /* the name of the pad */
GST_PAD_SINK, /* the direction of the pad */
GST_PAD_ALWAYS, /* when this pad will be present */
GST_STATIC_CAPS ( /* the capabilities of the padtemplate */
"audio/x-raw-int, "
"channels = (int) [ 1, 6 ]"
)
)
void
my_method (void)
{
GstPad *pad;
pad = gst_pad_new_from_template (GST_PAD_TEMPLATE_GET (my_template_factory), "sink");
...
}
</programlisting>
</example>
</para>
<para>
The following example shows you how to add the padtemplate to an elementfactory:
<programlisting>
gboolean
my_factory_init (GstPlugin *plugin)
{
GstElementFactory *factory;
factory = gst_element_factory_new ("my_factory", GST_TYPE_MYFACTORY, &amp;gst_myfactory_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_element_factory_add_pad_template (factory, GST_PAD_TEMPLATE_GET (my_template_factory));
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
return TRUE;
}
</programlisting>
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
#GstPad, #GstElementFactory
</para>
<!-- ##### SECTION Stability_Level ##### -->
<!-- ##### STRUCT GstPadTemplate ##### -->
<para>
The padtemplate object.
</para>
<!-- ##### SIGNAL GstPadTemplate::pad-created ##### -->
<para>
This signal is fired when an element creates a pad from this
template.
</para>
@gstpadtemplate: the object which received the signal.
@arg1: The pad that was created.
<!-- ##### STRUCT GstStaticPadTemplate ##### -->
<para>
</para>
@name_template:
@direction:
@presence:
@static_caps:
<!-- ##### MACRO GST_IS_PAD_FAST ##### -->
<para>
</para>
@obj:
<!-- ##### MACRO GST_PAD_TEMPLATE_NAME_TEMPLATE ##### -->
<para>
Get the nametemplate of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PAD_TEMPLATE_DIRECTION ##### -->
<para>
Get the direction of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PAD_TEMPLATE_PRESENCE ##### -->
<para>
Get the presence of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PAD_TEMPLATE_CAPS ##### -->
<para>
Get a handle to the padtemplate #GstCaps
</para>
@templ: the template to query
<!-- ##### MACRO GST_PAD_TEMPLATE_IS_FIXED ##### -->
<para>
Check if the properties of the padtemplate are fixed
</para>
@templ: the template to query
<!-- ##### ENUM GstPadTemplateFlags ##### -->
<para>
Flags for the padtemplate
</para>
@GST_PAD_TEMPLATE_FIXED: the padtemplate has no variable properties
@GST_PAD_TEMPLATE_FLAG_LAST: first flag that can be used by subclasses.
<!-- ##### FUNCTION gst_pad_template_new ##### -->
<para>
</para>
@name_template:
@direction:
@presence:
@caps:
@Returns:
<!-- # Unused Parameters # -->
@Varargs:
<!-- ##### FUNCTION gst_static_pad_template_get ##### -->
<para>
</para>
@pad_template:
@Returns:
<!-- # Unused Parameters # -->
@templ:
<!-- ##### FUNCTION gst_pad_template_get_caps ##### -->
<para>
</para>
@templ:
@Returns: