| /* GStreamer |
| * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de> |
| * |
| * gsttypefindfactory.c: typefinding subsystem |
| * |
| * 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., 51 Franklin St, Fifth Floor, |
| * Boston, MA 02110-1301, USA. |
| */ |
| |
| /** |
| * SECTION:gsttypefindfactory |
| * @short_description: Information about registered typefind functions |
| * |
| * These functions allow querying informations about registered typefind |
| * functions. How to create and register these functions is described in |
| * the section <link linkend="gstreamer-Writing-typefind-functions"> |
| * "Writing typefind functions"</link>. |
| * |
| * The following example shows how to write a very simple typefinder that |
| * identifies the given data. You can get quite a bit more complicated than |
| * that though. |
| * |[<!-- language="C" --> |
| * typedef struct { |
| * guint8 *data; |
| * guint size; |
| * guint probability; |
| * GstCaps *data; |
| * } MyTypeFind; |
| * static void |
| * my_peek (gpointer data, gint64 offset, guint size) |
| * { |
| * MyTypeFind *find = (MyTypeFind *) data; |
| * if (offset >= 0 && offset + size <= find->size) { |
| * return find->data + offset; |
| * } |
| * return NULL; |
| * } |
| * static void |
| * my_suggest (gpointer data, guint probability, GstCaps *caps) |
| * { |
| * MyTypeFind *find = (MyTypeFind *) data; |
| * if (probability > find->probability) { |
| * find->probability = probability; |
| * gst_caps_replace (&find->caps, caps); |
| * } |
| * } |
| * static GstCaps * |
| * find_type (guint8 *data, guint size) |
| * { |
| * GList *walk, *type_list; |
| * MyTypeFind find = {data, size, 0, NULL}; |
| * GstTypeFind gst_find = {my_peek, my_suggest, &find, }; |
| * walk = type_list = gst_type_find_factory_get_list (); |
| * while (walk) { |
| * GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (walk->data); |
| * walk = g_list_next (walk) |
| * gst_type_find_factory_call_function (factory, &gst_find); |
| * } |
| * g_list_free (type_list); |
| * return find.caps; |
| * }; |
| * ]| |
| */ |
| |
| #include "gst_private.h" |
| #include "gstinfo.h" |
| #include "gsttypefind.h" |
| #include "gsttypefindfactory.h" |
| #include "gstregistry.h" |
| |
| GST_DEBUG_CATEGORY (type_find_debug); |
| #define GST_CAT_DEFAULT type_find_debug |
| |
| static void gst_type_find_factory_dispose (GObject * object); |
| |
| #define _do_init \ |
| { \ |
| GST_DEBUG_CATEGORY_INIT (type_find_debug, "GST_TYPEFIND", \ |
| GST_DEBUG_FG_GREEN, "typefinding subsystem"); \ |
| } |
| |
| #define gst_type_find_factory_parent_class parent_class |
| G_DEFINE_TYPE_WITH_CODE (GstTypeFindFactory, gst_type_find_factory, |
| GST_TYPE_PLUGIN_FEATURE, _do_init); |
| |
| static void |
| gst_type_find_factory_class_init (GstTypeFindFactoryClass * klass) |
| { |
| GObjectClass *object_class = G_OBJECT_CLASS (klass); |
| |
| object_class->dispose = gst_type_find_factory_dispose; |
| } |
| |
| static void |
| gst_type_find_factory_init (GstTypeFindFactory * factory) |
| { |
| factory->user_data = factory; |
| factory->user_data_notify = NULL; |
| } |
| |
| static void |
| gst_type_find_factory_dispose (GObject * object) |
| { |
| GstTypeFindFactory *factory = GST_TYPE_FIND_FACTORY (object); |
| |
| if (factory->caps) { |
| gst_caps_unref (factory->caps); |
| factory->caps = NULL; |
| } |
| if (factory->extensions) { |
| g_strfreev (factory->extensions); |
| factory->extensions = NULL; |
| } |
| if (factory->user_data_notify && factory->user_data) { |
| factory->user_data_notify (factory->user_data); |
| factory->user_data = NULL; |
| } |
| |
| G_OBJECT_CLASS (parent_class)->dispose (object); |
| } |
| |
| /** |
| * gst_type_find_factory_get_list: |
| * |
| * Gets the list of all registered typefind factories. You must free the |
| * list using gst_plugin_feature_list_free(). |
| * |
| * The returned factories are sorted by highest rank first, and then by |
| * factory name. |
| * |
| * Free-function: gst_plugin_feature_list_free |
| * |
| * Returns: (transfer full) (element-type Gst.TypeFindFactory): the list of all |
| * registered #GstTypeFindFactory. |
| */ |
| GList * |
| gst_type_find_factory_get_list (void) |
| { |
| return gst_registry_get_feature_list (gst_registry_get (), |
| GST_TYPE_TYPE_FIND_FACTORY); |
| } |
| |
| /** |
| * gst_type_find_factory_get_caps: |
| * @factory: A #GstTypeFindFactory |
| * |
| * Gets the #GstCaps associated with a typefind factory. |
| * |
| * Returns: (transfer none): the #GstCaps associated with this factory |
| */ |
| GstCaps * |
| gst_type_find_factory_get_caps (GstTypeFindFactory * factory) |
| { |
| g_return_val_if_fail (GST_IS_TYPE_FIND_FACTORY (factory), NULL); |
| |
| return factory->caps; |
| } |
| |
| /** |
| * gst_type_find_factory_get_extensions: |
| * @factory: A #GstTypeFindFactory |
| * |
| * Gets the extensions associated with a #GstTypeFindFactory. The returned |
| * array should not be changed. If you need to change stuff in it, you should |
| * copy it using g_strdupv(). This function may return %NULL to indicate |
| * a 0-length list. |
| * |
| * Returns: (transfer none) (array zero-terminated=1) (element-type utf8) (nullable): |
| * a %NULL-terminated array of extensions associated with this factory |
| */ |
| const gchar *const * |
| gst_type_find_factory_get_extensions (GstTypeFindFactory * factory) |
| { |
| g_return_val_if_fail (GST_IS_TYPE_FIND_FACTORY (factory), NULL); |
| |
| return (const gchar * const *) factory->extensions; |
| } |
| |
| /** |
| * gst_type_find_factory_call_function: |
| * @factory: A #GstTypeFindFactory |
| * @find: (transfer none): a properly setup #GstTypeFind entry. The get_data |
| * and suggest_type members must be set. |
| * |
| * Calls the #GstTypeFindFunction associated with this factory. |
| */ |
| void |
| gst_type_find_factory_call_function (GstTypeFindFactory * factory, |
| GstTypeFind * find) |
| { |
| GstTypeFindFactory *new_factory; |
| |
| g_return_if_fail (GST_IS_TYPE_FIND_FACTORY (factory)); |
| g_return_if_fail (find != NULL); |
| g_return_if_fail (find->peek != NULL); |
| g_return_if_fail (find->suggest != NULL); |
| |
| new_factory = |
| GST_TYPE_FIND_FACTORY (gst_plugin_feature_load (GST_PLUGIN_FEATURE |
| (factory))); |
| if (new_factory) { |
| if (new_factory->function) |
| new_factory->function (find, new_factory->user_data); |
| gst_object_unref (new_factory); |
| } |
| } |
| |
| /** |
| * gst_type_find_factory_has_function: |
| * @factory: A #GstTypeFindFactory |
| * |
| * Check whether the factory has a typefind function. Typefind factories |
| * without typefind functions are a last-effort fallback mechanism to |
| * e.g. assume a certain media type based on the file extension. |
| * |
| * Returns: %TRUE if the factory has a typefind functions set, otherwise %FALSE |
| */ |
| gboolean |
| gst_type_find_factory_has_function (GstTypeFindFactory * factory) |
| { |
| g_return_val_if_fail (GST_IS_TYPE_FIND_FACTORY (factory), FALSE); |
| |
| return (factory->function != NULL); |
| } |