/* GStreamer

 * Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>

 *

 * gsttypefind.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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

/**

 * SECTION:gsttypefind

 * @short_description: Stream type detection

 *

 * The following functions allow you to detect the media type of an unknown

 * stream.

 *

 * Last reviewed on 2005-11-09 (0.9.4)

 */

#include "gst_private.h"

#include "gstinfo.h"

#include "gsttypefind.h"

#include "gstregistry.h"

#include "gsttypefindfactory.h"

GST_DEBUG_CATEGORY_EXTERN (type_find_debug);

#define GST_CAT_DEFAULT type_find_debug

#ifdef __SYMBIAN32__

EXPORT_C

#endif

GType

gst_type_find_get_type (void)

{

  static GType typefind_type = 0;

  if (G_UNLIKELY (typefind_type == 0)) {

    typefind_type = g_pointer_type_register_static ("GstTypeFind");

  }

  return typefind_type;

}

/**

 * gst_type_find_register:

 * @plugin: A #GstPlugin, or NULL for a static typefind function (note that

 *    passing NULL only works in GStreamer 0.10.16 and later)

 * @name: The name for registering

 * @rank: The rank (or importance) of this typefind function

 * @func: The #GstTypeFindFunction to use

 * @extensions: Optional extensions that could belong to this type

 * @possible_caps: Optionally the caps that could be returned when typefinding

 *                 succeeds

 * @data: Optional user data. This user data must be available until the plugin

 *        is unloaded.

 * @data_notify: a #GDestroyNotify that will be called on @data when the plugin

 *        is unloaded.

 *

 * Registers a new typefind function to be used for typefinding. After

 * registering this function will be available for typefinding.

 * This function is typically called during an element's plugin initialization.

 *

 * Returns: TRUE on success, FALSE otherwise

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gboolean

gst_type_find_register (GstPlugin * plugin, const gchar * name, guint rank,

    GstTypeFindFunction func, gchar ** extensions,

    const GstCaps * possible_caps, gpointer data, GDestroyNotify data_notify)

{

  GstTypeFindFactory *factory;

  g_return_val_if_fail (name != NULL, FALSE);

  GST_INFO ("registering typefind function for %s", name);

  factory = g_object_new (GST_TYPE_TYPE_FIND_FACTORY, NULL);

  GST_DEBUG_OBJECT (factory, "using new typefind factory for %s", name);

  g_assert (GST_IS_TYPE_FIND_FACTORY (factory));

  gst_plugin_feature_set_rank (GST_PLUGIN_FEATURE (factory), rank);

  if (factory->extensions)

    g_strfreev (factory->extensions);

  factory->extensions = g_strdupv (extensions);

  gst_caps_replace (&factory->caps, (GstCaps *) possible_caps);

  factory->function = func;

  factory->user_data = data;

  factory->user_data_notify = data_notify;

  if (plugin && plugin->desc.name) {

    GST_PLUGIN_FEATURE (factory)->plugin_name = plugin->desc.name;      /* interned string */

  } else {

    GST_PLUGIN_FEATURE (factory)->plugin_name = "NULL";

  }

  GST_PLUGIN_FEATURE (factory)->loaded = TRUE;

  gst_registry_add_feature (gst_registry_get_default (),

      GST_PLUGIN_FEATURE (factory));

  return TRUE;

}

/*** typefind function interface **********************************************/

/**

 * gst_type_find_peek:

 * @find: The #GstTypeFind object the function was called with

 * @offset: The offset

 * @size: The number of bytes to return

 *

 * Returns the @size bytes of the stream to identify beginning at offset. If

 * offset is a positive number, the offset is relative to the beginning of the

 * stream, if offset is a negative number the offset is relative to the end of

 * the stream. The returned memory is valid until the typefinding function

 * returns and must not be freed.

 *

 * Returns: the requested data, or NULL if that data is not available.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

guint8 *

gst_type_find_peek (GstTypeFind * find, gint64 offset, guint size)

{

  g_return_val_if_fail (find->peek != NULL, NULL);

  return find->peek (find->data, offset, size);

}

/**

 * gst_type_find_suggest:

 * @find: The #GstTypeFind object the function was called with

 * @probability: The probability in percent that the suggestion is right

 * @caps: The fixed #GstCaps to suggest

 *

 * If a #GstTypeFindFunction calls this function it suggests the caps with the

 * given probability. A #GstTypeFindFunction may supply different suggestions

 * in one call.

 * It is up to the caller of the #GstTypeFindFunction to interpret these values.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

void

gst_type_find_suggest (GstTypeFind * find, guint probability,

    const GstCaps * caps)

{

  g_return_if_fail (find->suggest != NULL);

  g_return_if_fail (probability <= 100);

  g_return_if_fail (caps != NULL);

  g_return_if_fail (gst_caps_is_fixed (caps));

  find->suggest (find->data, probability, caps);

}

/**

 * gst_type_find_get_length:

 * @find: The #GstTypeFind the function was called with

 *

 * Get the length of the data stream.

 *

 * Returns: The length of the data stream, or 0 if it is not available.

 */

#ifdef __SYMBIAN32__

EXPORT_C

#endif

guint64

gst_type_find_get_length (GstTypeFind * find)

{

  if (find->get_length == NULL)

    return 0;

  return find->get_length (find->data);

}