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