Name
GstPadTemplate -- Describe the media type of a pad.
Synopsis
#include <gst/gst.h>
enum GstPadPresence;
struct GstPadTemplate;
#define GST_PADTEMPLATE_CAPS (templ)
#define GST_PADTEMPLATE_DIRECTION (templ)
#define GST_PADTEMPLATE_NAME_TEMPLATE (templ)
#define GST_PADTEMPLATE_PRESENCE (templ)
#define GST_PADTEMPLATE_NEW (padname, dir, pres, a...)
#define GST_PADTEMPLATE_FACTORY (name, padname, dir, pres, a...)
#define GST_PADTEMPLATE_GET (fact)
#define GST_PADTEMPLATE_FIXED (templ)
#define GST_PADTEMPLATE_IS_FIXED (templ)
GstPadTemplate* gst_padtemplate_new (gchar *name_template,
GstPadDirection direction,
GstPadPresence presence,
GstCaps *caps,
...);
GstPadTemplate* gst_padtemplate_load_thyself
(xmlNodePtr parent);
xmlNodePtr gst_padtemplate_save_thyself (GstPadTemplate *templ,
xmlNodePtr parent);
GstCaps* gst_padtemplate_get_caps (GstPadTemplate *templ);
GstCaps* gst_padtemplate_get_caps_by_name
(GstPadTemplate *templ,
const gchar *name);
|
Description
Padtemplates describe the possible media types a pad or an elementfactory can
handle.
Pad and PadTemplates have GstCaps attached to it to describe the media type they
are capable of dealing with. gst_padtemplate_get_caps() is used to get the
caps of a padtemplate. It's not possible to modify the caps of a padtemplate after
creation.
Padtemplates can be created with gst_padtemplate_new() or with the convenient
GST_PADTEMPLATE_FACTORY() macro. A padtemplate can be used to create a pad or
to add to an elementfactory.
The following code example shows the code to create a pad from a padtemplate.
GST_PADTEMPLATE_FACTORY (my_template_factory,
"sink", /* the name of the pad */
GST_PAD_SINK, /* the direction of the pad */
GST_PAD_ALWAYS, /* when this pad will be present */
GST_CAPS_NEW ( /* the capabilities of the padtemplate */
"my_caps",
"audio/raw",
"format", GST_PROPS_STRING ("int"),
"channels", GST_PROPS_INT_RANGE (1, 6)
)
)
void
my_method (void)
{
GstPad *pad;
pad = gst_pad_new_from_template (GST_PADTEMPLATE_GET (my_template_factory), "sink");
...
} |
The following example shows you how to add the padtemplate to an elementfactory:
gboolean
my_factory_init (GstPlugin *plugin)
{
GstElementFactory *factory;
factory = gst_elementfactory_new ("my_factory", GST_TYPE_MYFACTORY, &gst_myfactory_details);
g_return_val_if_fail (factory != NULL, FALSE);
gst_elementfactory_add_padtemplate (factory, GST_PADTEMPLATE_GET (my_template_factory));
gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
return TRUE;
}
|
Details
enum GstPadPresence
typedef enum {
GST_PAD_ALWAYS,
GST_PAD_SOMETIMES,
GST_PAD_REQUEST,
} GstPadPresence; |
Indicates when this pad will become available.
struct GstPadTemplate
struct GstPadTemplate {
GstObject object;
gchar *name_template;
GstPadDirection direction;
GstPadPresence presence;
GstCaps *caps;
gboolean fixed;
}; |
GST_PADTEMPLATE_CAPS()
#define GST_PADTEMPLATE_CAPS(templ) (((GstPadTemplate *)(templ))->caps) |
Get a handle to the padtemplate GstCaps
GST_PADTEMPLATE_DIRECTION()
#define GST_PADTEMPLATE_DIRECTION(templ) (((GstPadTemplate *)(templ))->direction) |
Get the direction of the padtemplate.
GST_PADTEMPLATE_NAME_TEMPLATE()
#define GST_PADTEMPLATE_NAME_TEMPLATE(templ) (((GstPadTemplate *)(templ))->name_template) |
Get the nametemplate of the padtemplate.
GST_PADTEMPLATE_PRESENCE()
#define GST_PADTEMPLATE_PRESENCE(templ) (((GstPadTemplate *)(templ))->presence) |
Get the presence of the padtemplate.
GST_PADTEMPLATE_NEW()
#define GST_PADTEMPLATE_NEW(padname, dir, pres, a...) |
Create a new padtemplate.
GST_PADTEMPLATE_FACTORY()
#define GST_PADTEMPLATE_FACTORY(name, padname, dir, pres, a...) |
Create a factory for a padtemplate. This can be used if you only want one instance
of the padtemplate. Use GST_PADTEMPLATE_GET() to get the unique padtemplate.
GST_PADTEMPLATE_GET()
#define GST_PADTEMPLATE_GET(fact) (fact)() |
Get the padtemplate of the factory created with GST_PADTEMPLATE_FACTORY()
GST_PADTEMPLATE_FIXED()
#define GST_PADTEMPLATE_FIXED(templ) (((GstPadTemplate *)(templ))->fixed) |
GST_PADTEMPLATE_IS_FIXED()
#define GST_PADTEMPLATE_IS_FIXED(templ) (GST_PADTEMPLATE_FIXED(templ) == TRUE) |
gst_padtemplate_new ()
Creates a new padtemplate from the given arguments.
gst_padtemplate_load_thyself ()
Loads a padtemplate from the XML tree.
gst_padtemplate_save_thyself ()
xmlNodePtr gst_padtemplate_save_thyself (GstPadTemplate *templ,
xmlNodePtr parent); |
Saves the padtemplate into XML.
gst_padtemplate_get_caps ()
Get the capabilities of the padtemplate
gst_padtemplate_get_caps_by_name ()
Get the capability with the given name from this padtemplate.