1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
|
<!-- ##### 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_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.
</para>
<para>
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.
</para>
<para>
The following code example shows the code to create a pad from a padtemplate.
<programlisting>
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");
...
}
</programlisting>
</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_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;
}
</programlisting>
</para>
<!-- ##### SECTION See_Also ##### -->
<para>
#GstPad, #GstElementFactory
</para>
<!-- ##### ENUM GstPadPresence ##### -->
<para>
Indicates when this pad will become available.
</para>
@GST_PAD_ALWAYS: the pad is always available
@GST_PAD_SOMETIMES: the pad will become available depending on the media stream
@GST_PAD_REQUEST: th pad is only available on request with
gst_element_request_pad_by_name() or gst_element_request_compatible_pad().
<!-- ##### STRUCT GstPadTemplate ##### -->
<para>
</para>
@object:
@name_template:
@direction:
@presence:
@caps:
<!-- ##### MACRO GST_PADTEMPLATE_CAPS ##### -->
<para>
Get a handle to the padtemplate #GstCaps
</para>
@templ: the template to query
<!-- ##### MACRO GST_PADTEMPLATE_DIRECTION ##### -->
<para>
Get the direction of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PADTEMPLATE_NAME_TEMPLATE ##### -->
<para>
Get the nametemplate of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PADTEMPLATE_PRESENCE ##### -->
<para>
Get the presence of the padtemplate.
</para>
@templ: the template to query
<!-- ##### MACRO GST_PADTEMPLATE_NEW ##### -->
<para>
Create a new padtemplate.
</para>
@padname: the nametemplate for the pads that will be created with this template
@dir: the direction of the pads.
@pres: the presence of the pads.
@a...: the capabilities of this padtemplate usually created with GST_CAPS_NEW()
<!-- ##### MACRO GST_PADTEMPLATE_FACTORY ##### -->
<para>
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.
</para>
@name: th name of the factory
@padname: the nametemplate of the pads
@dir: the direction of the pads.
@pres: the presence of the pads.
@a...: the capabilities of this padtemplate, usually created with GST_CAPS_NEW()
<!-- ##### MACRO GST_PADTEMPLATE_GET ##### -->
<para>
Get the padtemplate of the factory created with GST_PADTEMPLATE_FACTORY()
</para>
@fact: the factory name to get the padtemplate from.
<!-- ##### FUNCTION gst_padtemplate_new ##### -->
<para>
</para>
@name_template:
@direction:
@presence:
@caps:
@Varargs:
@Returns:
<!-- ##### FUNCTION gst_padtemplate_load_thyself ##### -->
<para>
</para>
@parent:
@Returns:
<!-- ##### FUNCTION gst_padtemplate_save_thyself ##### -->
<para>
</para>
@templ:
@parent:
@Returns:
<!-- ##### FUNCTION gst_padtemplate_get_caps ##### -->
<para>
</para>
@templ:
@Returns:
<!-- ##### FUNCTION gst_padtemplate_get_caps_by_name ##### -->
<para>
</para>
@templ:
@name:
@Returns:
|
