summaryrefslogtreecommitdiff
path: root/gst/gstpluginfeature.c
blob: c665f2c52382424037b0db5278a23099dd9c6699 (plain)
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
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
/* GStreamer
 * Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
 *                    2000 Wim Taymans <wtay@chello.be>
 *
 * gstpluginfeature.c: Abstract base class for all plugin features
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */
/**
 * SECTION:gstpluginfeature
 * @short_description: Base class for contents of a GstPlugin
 * @see_also: #GstPlugin
 *
 * This is a base class for anything that can be added to a #GstPlugin.
 */

#include "gst_private.h"

#include "gstpluginfeature.h"
#include "gstplugin.h"
#include "gstregistry.h"
#include "gstinfo.h"

#include <string.h>

#define GST_CAT_DEFAULT GST_CAT_PLUGIN_LOADING

static void gst_plugin_feature_class_init (GstPluginFeatureClass * klass);
static void gst_plugin_feature_init (GstPluginFeature * feature);
static void gst_plugin_feature_finalize (GObject * object);

/* static guint gst_plugin_feature_signals[LAST_SIGNAL] = { 0 }; */

G_DEFINE_ABSTRACT_TYPE (GstPluginFeature, gst_plugin_feature, GST_TYPE_OBJECT);
GstObjectClass *parent_class = NULL;

static void
gst_plugin_feature_class_init (GstPluginFeatureClass * klass)
{
  parent_class = g_type_class_ref (GST_TYPE_OBJECT);

  G_OBJECT_CLASS (klass)->finalize =
      GST_DEBUG_FUNCPTR (gst_plugin_feature_finalize);
}

static void
gst_plugin_feature_init (GstPluginFeature * feature)
{

}

static void
gst_plugin_feature_finalize (GObject * object)
{
  GstPluginFeature *feature = GST_PLUGIN_FEATURE (object);

  GST_DEBUG ("finalizing feature %p", feature);
  g_free (feature->name);
  g_free (feature->plugin_name);

  G_OBJECT_CLASS (parent_class)->finalize (object);
}

/**
 * gst_plugin_feature_load:
 * @feature: the plugin feature to check
 *
 * Loads the plugin containing @feature if it's not already loaded. @feature is
 * unaffected; use the return value instead.
 *
 * Normally this function is used like this:
 *
 * <programlisting>
 * GstPluginFeature *loaded_feature;
 * loaded_feature = gst_plugin_feature_load (feature);
 * // presumably, we're no longer interested in the potentially-unloaded feature
 * gst_object_unref (feature);
 * feature = loaded_feature;
 * </programlisting>
 *
 * Returns: A reference to the loaded feature, or NULL on error.
 */
GstPluginFeature *
gst_plugin_feature_load (GstPluginFeature * feature)
{
  GstPlugin *plugin;
  GstPluginFeature *real_feature;

  g_return_val_if_fail (feature != NULL, FALSE);
  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), FALSE);

  GST_DEBUG ("loading plugin for feature %p", feature);
  if (feature->loaded)
    return feature;

  GST_DEBUG ("loading plugin %s", feature->plugin_name);
  plugin = gst_plugin_load_by_name (feature->plugin_name);
  if (!plugin) {
    g_critical ("Failed to load plugin containing feature '%s'.",
        GST_PLUGIN_FEATURE_NAME (feature));
    return NULL;
  }
  GST_DEBUG ("loaded plugin %s", feature->plugin_name);
  gst_object_unref (plugin);

  real_feature =
      gst_registry_lookup_feature (gst_registry_get_default (), feature->name);

  if (real_feature == NULL) {
    GST_INFO
        ("Loaded plugin containing feature '%s', but feature disappeared.",
        feature->name);
  } else if (!real_feature->loaded) {
    GST_INFO ("Tried to load plugin containing feature '%s', but feature was "
        "not found.", real_feature->name);
    return NULL;
  }

  return real_feature;
}

gboolean
gst_plugin_feature_type_name_filter (GstPluginFeature * feature,
    GstTypeNameData * data)
{
  return ((data->type == 0 || data->type == G_OBJECT_TYPE (feature)) &&
      (data->name == NULL
          || !strcmp (data->name, GST_PLUGIN_FEATURE_NAME (feature))));
}

/**
 * gst_plugin_feature_set_name:
 * @feature: a feature
 * @name: the name to set
 *
 * Sets the name of a plugin feature. The name uniquely identifies a feature
 * within all features of the same type. Renaming a plugin feature is not 
 * allowed. A copy is made of the name so you should free the supplied @name
 * after calling this function.
 */
void
gst_plugin_feature_set_name (GstPluginFeature * feature, const gchar * name)
{
  g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));
  g_return_if_fail (name != NULL);

  if (feature->name) {
    g_return_if_fail (strcmp (feature->name, name) == 0);
  } else {
    feature->name = g_strdup (name);
  }
  gst_object_set_name (GST_OBJECT (feature), feature->name);
}

/**
 * gst_plugin_feature_get_name:
 * @feature: a feature
 *
 * Gets the name of a plugin feature.
 *
 * Returns: the name
 */
G_CONST_RETURN gchar *
gst_plugin_feature_get_name (GstPluginFeature * feature)
{
  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), NULL);

  return feature->name;
}

/**
 * gst_plugin_feature_set_rank:
 * @feature: feature to rank
 * @rank: rank value - higher number means more priority rank
 *
 * Specifies a rank for a plugin feature, so that autoplugging uses
 * the most appropriate feature.
 */
void
gst_plugin_feature_set_rank (GstPluginFeature * feature, guint rank)
{
  g_return_if_fail (feature != NULL);
  g_return_if_fail (GST_IS_PLUGIN_FEATURE (feature));

  feature->rank = rank;
}

/**
 * gst_plugin_feature_get rank:
 * @feature: a feature
 *
 * Gets the rank of a plugin feature.
 *
 * Returns: The rank of the feature
 */
guint
gst_plugin_feature_get_rank (GstPluginFeature * feature)
{
  g_return_val_if_fail (GST_IS_PLUGIN_FEATURE (feature), GST_RANK_NONE);

  return feature->rank;
}

/**
 * gst_plugin_feature_list_free:
 * @list: list of #GstPluginFeature
 *
 * Unrefs each member of @list, then frees the list.
 */
void
gst_plugin_feature_list_free (GList * list)
{
  GList *g;

  for (g = list; g; g = g->next) {
    GstPluginFeature *feature = GST_PLUGIN_FEATURE (g->data);

    gst_object_unref (feature);
  }
  g_list_free (list);
}