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/* GStreamer
* Copyright (C) 2003 Benjamin Otte <in7y118@public.uni-hamburg.de>
*
* gsttypefind.h: 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.
*/
#ifndef __GST_TYPE_FIND_H__
#define __GST_TYPE_FIND_H__
#include <gst/gstcaps.h>
#include <gst/gstplugin.h>
#include <gst/gstpluginfeature.h>
G_BEGIN_DECLS
/**
* GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM:
* @type_find: The type find name in lower case, with words separated by '_'.
* Used to generate `gst_type_find_register_*(GstPlugin* plugin)`.
* @register_func: pointer to a method with the format: `gboolean register_func (GstPlugin* plugin);`
*
* A convenience macro to define the entry point of a
* type find `gst_type_find_register_*(GstPlugin* plugin)` which uses
* register_func as the main registration method for the type find.
* As an example, you may define the type find named "custom-typefind"
* as following using `type_find_register_custom`:
*
* ```
* GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM (plugin, type_find_register_custom)
* ```
*
* Since: 1.20
*/
#define GST_TYPE_FIND_REGISTER_DEFINE_CUSTOM(type_find, register_func) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_type_find_register_, type_find) (GstPlugin * plugin) \
{ \
return register_func (plugin); \
} \
G_END_DECLS
/**
* GST_TYPE_FIND_REGISTER_DEFINE:
* @t_f: The type find name in lower case, with words separated by '_'.
* Used to generate `gst_type_find_register_*(GstPlugin* plugin)`.
* @t_f_n: The public name of the type find
* @r: The #GstRank of the type find (higher rank means more importance when autoplugging, see #GstRank)
* @func: The #GstTypeFindFunction to use
* @extensions: (nullable): Optional comma-separated list of extensions
* that could belong to this type
* @possible_caps: (nullable): 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.
*
* A convenience macro to define the entry point of a
* type find `gst_type_find_register_*(GstPlugin* plugin)`.
*
* Since: 1.20
*/
#define GST_TYPE_FIND_REGISTER_DEFINE(t_f, t_f_n, r, func, extensions, possible_caps, data, data_notify) \
G_BEGIN_DECLS \
gboolean G_PASTE (gst_type_find_register_, t_f) (GstPlugin * plugin) \
{ \
return gst_type_find_register (plugin, t_f_n, r, func, extensions, possible_caps, data, data_notify); \
} \
G_END_DECLS
/**
* GST_TYPE_FIND_REGISTER_DECLARE:
* @t_f: The type find name in lower case, with words separated by '_'.
*
* This macro can be used to declare a new type find.
* It has to be used in combination with #GST_TYPE_FIND_REGISTER_DEFINE macro
* and must be placed outside any block to declare the type find registration
* function.
*
* Since: 1.20
*/
#define GST_TYPE_FIND_REGISTER_DECLARE(t_f) \
G_BEGIN_DECLS \
gboolean G_PASTE(gst_type_find_register_, t_f) (GstPlugin * plugin); \
G_END_DECLS
/**
* GST_TYPE_FIND_REGISTER:
* @t_f: The type find name in lower case, with words separated by '_'.
* @plugin: The #GstPlugin where to register the type find.
*
* This macro can be used to register a type find into a #GstPlugin.
* This method will be usually called in the plugin init function
* but can also be called with a NULL plugin.
*
* Since: 1.20
*/
#define GST_TYPE_FIND_REGISTER(t_f, plugin) G_PASTE(gst_type_find_register_, t_f) (plugin)
#define GST_TYPE_TYPE_FIND (gst_type_find_get_type())
typedef struct _GstTypeFind GstTypeFind;
/**
* GstTypeFindFunction:
* @find: A #GstTypeFind structure
* @user_data: optional data to pass to the function
*
* A function that will be called by typefinding.
*/
typedef void (* GstTypeFindFunction) (GstTypeFind *find, gpointer user_data);
/**
* GstTypeFindProbability:
* @GST_TYPE_FIND_NONE: type undetected.
* @GST_TYPE_FIND_MINIMUM: unlikely typefind.
* @GST_TYPE_FIND_POSSIBLE: possible type detected.
* @GST_TYPE_FIND_LIKELY: likely a type was detected.
* @GST_TYPE_FIND_NEARLY_CERTAIN: nearly certain that a type was detected.
* @GST_TYPE_FIND_MAXIMUM: very certain a type was detected.
*
* The probability of the typefind function. Higher values have more certainty
* in doing a reliable typefind.
*/
typedef enum {
GST_TYPE_FIND_NONE = 0,
GST_TYPE_FIND_MINIMUM = 1,
GST_TYPE_FIND_POSSIBLE = 50,
GST_TYPE_FIND_LIKELY = 80,
GST_TYPE_FIND_NEARLY_CERTAIN = 99,
GST_TYPE_FIND_MAXIMUM = 100
} GstTypeFindProbability;
/**
* GstTypeFind:
* @peek: Method to peek data.
* @suggest: Method to suggest #GstCaps with a given probability.
* @data: The data used by the caller of the typefinding function.
* @get_length: Returns the length of current data.
*
* Object that stores typefind callbacks. To use with #GstTypeFindFactory.
*/
struct _GstTypeFind {
/* private to the caller of the typefind function */
const guint8 * (* peek) (gpointer data,
gint64 offset,
guint size);
void (* suggest) (gpointer data,
guint probability,
GstCaps *caps);
gpointer data;
/* optional */
guint64 (* get_length) (gpointer data);
/* <private> */
gpointer _gst_reserved[GST_PADDING];
};
/**
* gst_type_find_get_type: (attributes doc.skip=true)
*/
GST_API
GType gst_type_find_get_type (void);
/* typefind function interface */
GST_API
const guint8 * gst_type_find_peek (GstTypeFind * find,
gint64 offset,
guint size);
GST_API
void gst_type_find_suggest (GstTypeFind * find,
guint probability,
GstCaps * caps);
GST_API
void gst_type_find_suggest_empty_simple (GstTypeFind * find,
guint probability,
const char * media_type);
GST_API
void gst_type_find_suggest_simple (GstTypeFind * find,
guint probability,
const char * media_type,
const char * fieldname, ...) G_GNUC_NULL_TERMINATED;
GST_API
guint64 gst_type_find_get_length (GstTypeFind * find);
/* registration interface */
GST_API
gboolean gst_type_find_register (GstPlugin * plugin,
const gchar * name,
guint rank,
GstTypeFindFunction func,
const gchar * extensions,
GstCaps * possible_caps,
gpointer data,
GDestroyNotify data_notify);
G_END_DECLS
#endif /* __GST_TYPE_FIND_H__ */
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