plugable modules
[utils]

Plugable Module functions. More...

Classes
struct	GF_BaseInterface
	Base Interface. More...
Defines
#define	GF_DECL_MODULE_INTERFACE
	common module interface
#define	GF_REGISTER_MODULE_INTERFACE(_ifce, _ifce_type, _ifce_name, _ifce_author)
	module interface registration
Typedefs
typedef __tag_mod_man	GF_ModuleManager
Functions
GF_ModuleManager *	gf_modules_new (const char *directory, GF_Config *cfgFile)
	module manager construtcor
void	gf_modules_del (GF_ModuleManager *pm)
	module manager destructor
u32	gf_modules_refresh (GF_ModuleManager *pm)
	refreshes modules
u32	gf_modules_get_count (GF_ModuleManager *pm)
	get module count
const char *	gf_modules_get_file_name (GF_ModuleManager *pm, u32 index)
	get module file name
GF_BaseInterface *	gf_modules_load_interface (GF_ModuleManager *pm, u32 index, u32 InterfaceFamily)
	loads an interface
GF_BaseInterface *	gf_modules_load_interface_by_name (GF_ModuleManager *pm, const char *mod_name, u32 InterfaceFamily)
	loads an interface by module name
GF_Err	gf_modules_close_interface (GF_BaseInterface *interface_obj)
	interface shutdown
const char *	gf_modules_get_option (GF_BaseInterface *interface_obj, const char *secName, const char *keyName)
	interface option query
GF_Err	gf_modules_set_option (GF_BaseInterface *interface_obj, const char *secName, const char *keyName, const char *keyValue)
	interface option update
GF_Config *	gf_modules_get_config (GF_BaseInterface *ifce)
	get config fiole

---

Detailed Description

This section documents the plugable module functions of the GPAC framework. A module is a dynamic/shared library providing one or several interfaces to the GPAC framework. A module cannot provide several interfaces of the same type. Each module must export the following functions:

        Bool QueryInterface(u32 interface_type);

This function is used to query supported interfaces. It returns non zero if the module handles this interface type, 0 otherwise.

        GF_BaseInterface *LoadInterface(u32 interface_type);

This function is used to load an interface. It returns the interface object, NULL if error.

        void ShutdownInterface(GF_BaseInterface *interface);

This function is used to destroy an interface.

Each interface must begin with the interface macro in order to be type-casted to the base interface structure.

        struct {
                GF_DECL_MODULE_INTERFACE
                extensions;
        };

---

Define Documentation

#define GF_DECL_MODULE_INTERFACE

This is the module interface declaration macro. It must be placed first in an interface structure declaration.

#define GF_REGISTER_MODULE_INTERFACE	(	_ifce,
		_ifce_type,
		_ifce_name,
		_ifce_author		)

This is the module interface registration macro. A module must call this macro whenever creating a new interface.

• _ifce: interface being registered
• _ifce_type: the four character code defining the interface type.
• _ifce_name: a printable string giving the interface name (const char *).
• _ifce_author: a printable string giving the author name (const char *).
  This is a sample GPAC codec interface declaration:

  GF_BaseInterface *MyDecoderInterfaceLoad() {
          GF_MediaDecoder *ifce;
          GF_SAFEALLOC(ifce, GF_MediaDecoder);
          GF_REGISTER_MODULE_INTERFACE(ifce, GF_MEDIA_DECODER_INTERFACE, "Sample Decoder", "The Author")
          //follows any initialization private to the decoder
          return (GF_BaseInterface *)ifce;
  }
  

---

Function Documentation

GF_ModuleManager* gf_modules_new	(	const char *	directory,
		GF_Config *	cfgFile
	)

Constructs a module manager object.

Parameters:

	directory	absolute path to the directory where the manager shall look for modules
	cfgFile	GPAC configuration file handle. If this is NULL, the modules won't be able to share the configuration file with the rest of the GPAC framework.

Returns:

the module manager object

void gf_modules_del

(

GF_ModuleManager *

pm

)

Destroys the module manager

Parameters:

pm

the module manager

u32 gf_modules_refresh

(

GF_ModuleManager *

pm

)

Refreshes all modules in the manager directory and load unloaded ones

Parameters:

pm

the module manager

Returns:

the number of loaded modules

u32 gf_modules_get_count

(

GF_ModuleManager *

pm

)

Gets the number of modules found in the manager directory

Parameters:

pm

the module manager

Returns:

the number of loaded modules

const char* gf_modules_get_file_name	(	GF_ModuleManager *	pm,
		u32	index
	)

Gets a module shared library file name based on its index

Parameters:

	pm	the module manager
	index	the 0-based index of the module to query

Returns:

the name of the shared library module

GF_BaseInterface* gf_modules_load_interface	(	GF_ModuleManager *	pm,
		u32	index,
		u32	InterfaceFamily
	)

Loads an interface in the desired module.

Parameters:

	pm	the module manager
	index	the 0-based index of the module to load the interface from
	InterfaceFamily	type of the interface to load

Returns:

the interface object if found and loaded, NULL otherwise.

GF_BaseInterface* gf_modules_load_interface_by_name	(	GF_ModuleManager *	pm,
		const char *	mod_name,
		u32	InterfaceFamily
	)

Loads an interface in the desired module

Parameters:

	pm	the module manager
	mod_name	the name of the module (shared library file) or of the interface as declared when registered.
	InterfaceFamily	type of the interface to load

Returns:

the interface object if found and loaded, NULL otherwise.

GF_Err gf_modules_close_interface

(

GF_BaseInterface *

interface_obj

)

Closes an interface

Parameters:

interface_obj

the interface to close

const char* gf_modules_get_option	(	GF_BaseInterface *	interface_obj,
		const char *	secName,
		const char *	keyName
	)

Gets an option from the config file associated with the module manager

Parameters:

	interface_obj	the interface object used
	secName	the desired key parent section name
	keyName	the desired key name

Returns:

the desired key value if found, NULL otherwise.

GF_Err gf_modules_set_option	(	GF_BaseInterface *	interface_obj,
		const char *	secName,
		const char *	keyName,
		const char *	keyValue
	)

Sets an option in the config file associated with the module manager

Parameters:

	interface_obj	the interface object used
	secName	the desired key parent section name
	keyName	the desired key name
	keyValue	the desired key value

Note:

this will also create both section and key if they are not found in the configuration file

GF_Config* gf_modules_get_config

(

GF_BaseInterface *

ifce

)

Gets the configuration file for the module instance

Parameters:

interface_obj

the interface object used

Returns:

handle to the config file

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