|  |  |  | GStreamer 0.10 Core Reference Manual |  | 
|---|
| GstPadTemplateGstPadTemplate — Describe the media type of a pad. | 
#include <gst/gst.h>
            GstPadTemplate;
            GstStaticPadTemplate;
#define     GST_PAD_TEMPLATE_NAME_TEMPLATE  (templ)
#define     GST_PAD_TEMPLATE_DIRECTION      (templ)
#define     GST_PAD_TEMPLATE_PRESENCE       (templ)
#define     GST_PAD_TEMPLATE_CAPS           (templ)
#define     GST_PAD_TEMPLATE_IS_FIXED       (templ)
enum        GstPadTemplateFlags;
enum        GstPadPresence;
GstPadTemplate* gst_pad_template_new        (const gchar *name_template,
                                             GstPadDirection direction,
                                             GstPadPresence presence,
                                             GstCaps *caps);
GstPadTemplate* gst_static_pad_template_get (GstStaticPadTemplate *pad_template);
GstCaps*    gst_static_pad_template_get_caps
                                            (GstStaticPadTemplate *templ);
GstCaps*    gst_pad_template_get_caps       (GstPadTemplate *templ);
"pad-created" void user_function (GstPadTemplate *pad_template, GstPad *pad, gpointer user_data);
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_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.
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.
The following code example shows the code to create a pad from a padtemplate.
Example 12. Create a pad from a padtemplate
  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");
    ...
  }
  
The following example shows you how to add the padtemplate to an elementfactory:
  gboolean
  my_factory_init (GstPlugin *plugin)
  {
    GstElementFactory *factory;
    factory = gst_element_factory_new ("my_factory", GST_TYPE_MYFACTORY, &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;
  }
  
typedef struct {
  gchar           *name_template;
  GstPadDirection  direction;
  GstPadPresence   presence;
  GstStaticCaps   static_caps;
} GstStaticPadTemplate;
Structure describing the GstStaticPadTemplate.
| gchar * name_template; | the name of the template | 
| GstPadDirection direction; | the direction of the template | 
| GstPadPresence presence; | the presence of the template | 
| GstStaticCaps static_caps; | the caps of the template. | 
#define GST_PAD_TEMPLATE_NAME_TEMPLATE(templ) (((GstPadTemplate *)(templ))->name_template)
Get the nametemplate of the padtemplate.
| templ: | the template to query | 
#define GST_PAD_TEMPLATE_DIRECTION(templ) (((GstPadTemplate *)(templ))->direction)
Get the direction of the padtemplate.
| templ: | the template to query | 
#define GST_PAD_TEMPLATE_PRESENCE(templ) (((GstPadTemplate *)(templ))->presence)
Get the presence of the padtemplate.
| templ: | the template to query | 
#define GST_PAD_TEMPLATE_CAPS(templ) (((GstPadTemplate *)(templ))->caps)
Get a handle to the padtemplate GstCaps
| templ: | the template to query | 
#define GST_PAD_TEMPLATE_IS_FIXED(templ) (GST_OBJECT_FLAG_IS_SET(templ, GST_PAD_TEMPLATE_FIXED))
Check if the properties of the padtemplate are fixed
| templ: | the template to query | 
typedef enum {
  GST_PAD_TEMPLATE_FIXED        = (GST_OBJECT_FLAG_LAST << 0),
  /* padding */
  GST_PAD_TEMPLATE_FLAG_LAST    = (GST_OBJECT_FLAG_LAST << 4)
} GstPadTemplateFlags;
Flags for the padtemplate
| GST_PAD_TEMPLATE_FIXED | the padtemplate has no variable properties | 
| GST_PAD_TEMPLATE_FLAG_LAST | first flag that can be used by subclasses. | 
typedef enum {
  GST_PAD_ALWAYS,
  GST_PAD_SOMETIMES,
  GST_PAD_REQUEST
} GstPadPresence;
Indicates when this pad will become available.
| GST_PAD_ALWAYS | the pad is always available | 
| GST_PAD_SOMETIMES | the pad will become available depending on the media stream | 
| GST_PAD_REQUEST | the pad is only available on request with gst_element_request_pad_by_name()orgst_element_request_compatible_pad(). | 
GstPadTemplate* gst_pad_template_new (const gchar *name_template, GstPadDirection direction, GstPadPresence presence, GstCaps *caps);
Creates a new pad template with a name according to the given template and with the given arguments. This functions takes ownership of the provided caps, so be sure to not use them afterwards.
| name_template: | the name template. | 
| direction: | the GstPadDirection of the template. | 
| presence: | the GstPadPresence of the pad. | 
| caps: | a GstCaps set for the template. The caps are taken ownership of. | 
| Returns : | a new GstPadTemplate. | 
GstPadTemplate* gst_static_pad_template_get (GstStaticPadTemplate *pad_template);
Converts a GstStaticPadTemplate into a GstPadTemplate.
| pad_template: | the static pad template | 
| Returns : | a new GstPadTemplate. | 
GstCaps* gst_static_pad_template_get_caps (GstStaticPadTemplate *templ);
Gets the capabilities of the static pad template.
| templ: | a GstStaticPadTemplate to get capabilities of. | 
| Returns : | the GstCaps of the static pad template. If you need to keep a
reference to the caps, take a ref (see gst_caps_ref()). | 
GstCaps* gst_pad_template_get_caps (GstPadTemplate *templ);
Gets the capabilities of the pad template.
| templ: | a GstPadTemplate to get capabilities of. | 
| Returns : | the GstCaps of the pad template. If you need to keep a reference to
the caps, take a ref (see gst_caps_ref()). | 
void user_function (GstPadTemplate *pad_template, GstPad *pad, gpointer user_data);
This signal is fired when an element creates a pad from this template.
| pad_template: | the object which received the signal. | 
| pad: | the pad that was created. | 
| user_data: | user data set when the signal handler was connected. | 
| << GstPad | GstParse >> |