2 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
4 * gsttypefind.h: typefinding subsystem
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Library General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Library General Public License for more details.
16 * You should have received a copy of the GNU Library General Public
17 * License along with this library; if not, write to the
18 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
19 * Boston, MA 02111-1307, USA.
23 #include "gsttypefind.h"
24 #include "gstregistrypool.h"
26 GST_DEBUG_CATEGORY_STATIC (gst_type_find_debug);
27 #define GST_CAT_DEFAULT gst_type_find_debug
29 static void gst_type_find_factory_class_init (gpointer g_class,
31 static void gst_type_find_factory_init (GTypeInstance * instance,
33 static void gst_type_find_factory_dispose (GObject * object);
35 static void gst_type_find_factory_unload_thyself (GstPluginFeature * feature);
37 static void gst_type_find_load_plugin (GstTypeFind * find, gpointer data);
39 static GstPluginFeatureClass *parent_class = NULL;
42 gst_type_find_factory_get_type (void)
44 static GType typefind_type = 0;
47 static const GTypeInfo typefind_info = {
48 sizeof (GstTypeFindFactoryClass),
51 gst_type_find_factory_class_init,
54 sizeof (GstTypeFindFactory),
56 gst_type_find_factory_init,
59 typefind_type = g_type_register_static (GST_TYPE_PLUGIN_FEATURE,
60 "GstTypeFindFactory", &typefind_info, 0);
61 GST_DEBUG_CATEGORY_INIT (gst_type_find_debug, "GST_TYPEFIND",
62 GST_DEBUG_FG_GREEN, "typefinding subsystem");
68 gst_type_find_factory_class_init (gpointer g_class, gpointer class_data)
70 GstPluginFeatureClass *gstpluginfeature_class =
71 GST_PLUGIN_FEATURE_CLASS (g_class);
72 GObjectClass *object_class = G_OBJECT_CLASS (g_class);
74 parent_class = g_type_class_peek_parent (g_class);
76 object_class->dispose = gst_type_find_factory_dispose;
78 gstpluginfeature_class->unload_thyself =
79 GST_DEBUG_FUNCPTR (gst_type_find_factory_unload_thyself);
82 gst_type_find_factory_init (GTypeInstance * instance, gpointer g_class)
84 GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (instance);
86 factory->user_data = factory;
87 factory->function = gst_type_find_load_plugin;
90 gst_type_find_factory_dispose (GObject * object)
92 GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (object);
95 gst_caps_free (factory->caps);
98 if (factory->extensions) {
99 g_strfreev (factory->extensions);
100 factory->extensions = NULL;
104 gst_type_find_factory_unload_thyself (GstPluginFeature * feature)
106 GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (feature);
108 factory->function = gst_type_find_load_plugin;
109 factory->user_data = factory;
112 gst_type_find_load_plugin (GstTypeFind * find, gpointer data)
114 GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (data);
116 GST_DEBUG_OBJECT (factory, "need to load typefind function %s",
117 GST_PLUGIN_FEATURE_NAME (factory));
119 if (gst_plugin_feature_ensure_loaded (GST_PLUGIN_FEATURE (factory))) {
120 if (factory->function == gst_type_find_load_plugin) {
121 /* looks like we didn't get a real typefind function */
122 g_warning ("could not load valid typefind function for feature '%s'\n",
123 GST_PLUGIN_FEATURE_NAME (factory));
125 g_assert (factory->function);
126 gst_type_find_factory_call_function (factory, find);
132 * gst_type_find_factory_get_list:
134 * Gets the list of all registered typefind factories. You must free the
135 * list using g_list_free.
137 * Returns: the list of all registered typefind factories
140 gst_type_find_factory_get_list (void)
142 return gst_registry_pool_feature_list (GST_TYPE_TYPE_FIND_FACTORY);
146 * gst_type_find_factory_get_caps:
147 * @factory: a factory
149 * Gets the caps associated with a typefind factory.
151 * Returns: the #GstCaps associated with this factory
154 gst_type_find_factory_get_caps (const GstTypeFindFactory * factory)
156 g_return_val_if_fail (GST_IS_TYPE_FIND_FACTORY (factory), NULL);
158 return factory->caps;
162 * gst_type_find_factory_get_extensions:
163 * @factory: a factory
165 * Gets the extensions associated with a typefind factory. The returned
166 * array should not be changed. If you need to change stuff in it, you should
167 * copy it using g_stdupv(). This function may return NULL to indicate
170 * Returns: a NULL-terminated array of extensions associated with this factory
173 gst_type_find_factory_get_extensions (const GstTypeFindFactory * factory)
175 g_return_val_if_fail (GST_IS_TYPE_FIND_FACTORY (factory), NULL);
177 return factory->extensions;
181 * gst_type_find_factory_call_function:
182 * @factory: a factory
183 * @find: a properly setup #GstTypeFind entry. The get_data and suggest_type
184 * members must be set.
186 * Calls the typefinding function associated with this factory.
189 gst_type_find_factory_call_function (const GstTypeFindFactory * factory,
192 g_return_if_fail (GST_IS_TYPE_FIND_FACTORY (factory));
193 g_return_if_fail (find != NULL);
194 g_return_if_fail (find->peek != NULL);
195 g_return_if_fail (find->suggest != NULL);
197 /* should never happen */
198 g_assert (factory->function != NULL);
200 factory->function (find, factory->user_data);
204 * gst_type_find_register:
205 * @plugin: the GstPlugin to register with
206 * @name: the name for registering
207 * @rank: rank (or importance) of this typefind function
208 * @func: the function to use for typefinding
209 * @extensions: optional extensions that could belong to this type
210 * @possible_caps: optionally the caps that could be returned when typefinding succeeds
211 * @data: optional user data. This user data must be available until the plugin
214 * Registers a new typefind function to be used for typefinding. After
215 * registering this function will be available for typefinding.
216 * This function is typically called during an element's plugin initialization.
218 * Returns: TRUE on success, FALSE otherwise
221 gst_type_find_register (GstPlugin * plugin, const gchar * name, guint rank,
222 GstTypeFindFunction func, gchar ** extensions,
223 const GstCaps * possible_caps, gpointer data)
225 GstTypeFindFactory *factory;
227 g_return_val_if_fail (plugin != NULL, FALSE);
228 g_return_val_if_fail (name != NULL, FALSE);
229 g_return_val_if_fail (func != NULL, FALSE);
231 GST_INFO ("registering typefind function for %s", name);
233 GST_TYPE_FIND_FACTORY (gst_registry_pool_find_feature (name,
234 GST_TYPE_TYPE_FIND_FACTORY));
236 factory = g_object_new (GST_TYPE_TYPE_FIND_FACTORY, NULL);
237 GST_DEBUG_OBJECT (factory, "using new typefind factory for %s", name);
238 g_assert (GST_IS_TYPE_FIND_FACTORY (factory));
239 gst_plugin_feature_set_name (GST_PLUGIN_FEATURE (factory), name);
241 GST_DEBUG_OBJECT (factory, "using old typefind factory for %s", name);
244 gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE (factory), rank);
245 if (factory->extensions)
246 g_strfreev (factory->extensions);
248 factory->extensions = g_strdupv (extensions);
249 gst_caps_replace (&factory->caps, gst_caps_copy (possible_caps));
250 factory->function = func;
251 factory->user_data = data;
253 gst_plugin_add_feature (plugin, GST_PLUGIN_FEATURE (factory));
258 /*** typefind function interface **********************************************/
261 * gst_type_find_peek:
262 * @find: the find object the function was called with
263 * @offset: the offset
264 * @size: the number of bytes to return
266 * Returns size bytes of the stream to identify beginning at offset. If offset
267 * is a positive number, the offset is relative to the beginning of the stream,
268 * if offset is a negative number the offset is relative to the end of the
269 * stream. The returned memory is valid until the typefinding function returns
270 * and must not be freed.
271 * If NULL is returned, that data is not available.
273 * Returns: the requested data or NULL if that data is not available.
276 gst_type_find_peek (GstTypeFind * find, gint64 offset, guint size)
278 g_return_val_if_fail (find->peek != NULL, NULL);
280 return find->peek (find->data, offset, size);
284 * gst_type_find_suggest:
285 * @find: the find object the function was called with
286 * @probability: the probability in percent that the suggestion is right
287 * @caps: the fixed caps to suggest
289 * If a typefind function calls this function it suggests the caps with the
290 * given probability. A typefind function may supply different suggestions
292 * It is up to the caller of the typefind function to interpret these values.
295 gst_type_find_suggest (GstTypeFind * find, guint probability,
296 const GstCaps * caps)
298 g_return_if_fail (find->suggest != NULL);
299 g_return_if_fail (probability <= 100);
300 g_return_if_fail (caps != NULL);
301 g_return_if_fail (gst_caps_is_fixed (caps));
303 find->suggest (find->data, probability, caps);
307 * gst_type_find_get_length:
308 * @find: the find object the function was called with
310 * Get the length of the data stream.
312 * Returns: the length of the data stream or 0 if it is not available.
315 gst_type_find_get_length (GstTypeFind * find)
317 if (find->get_length == NULL)
320 return find->get_length (find->data);