libgpac  0.4.5
Classes | Defines | Typedefs | Functions
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 struct __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
const char * gf_module_get_file_name (GF_BaseInterface *ifce)
 get module file name
GF_BaseInterfacegf_modules_load_interface (GF_ModuleManager *pm, u32 index, u32 InterfaceFamily)
 loads an interface
GF_BaseInterfacegf_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:

        u32 *QueryInterfaces(u32 interface_type);

This function is used to query supported interfaces. It returns a zero-terminated array of supported interface types.

        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

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:
directoryabsolute path to the directory where the manager shall look for modules
cfgFileGPAC 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:
pmthe module manager
u32 gf_modules_refresh ( GF_ModuleManager *  pm)

Refreshes all modules in the manager directory and load unloaded ones

Parameters:
pmthe 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:
pmthe 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:
pmthe module manager
indexthe 0-based index of the module to query
Returns:
the name of the shared library module
const char* gf_module_get_file_name ( GF_BaseInterface ifce)

Gets a module shared library file name based on its index

Parameters:
ifcethe module instance 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:
pmthe module manager
indexthe 0-based index of the module to load the interface from
InterfaceFamilytype 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:
pmthe module manager
mod_namethe name of the module (shared library file) or of the interface as declared when registered.
InterfaceFamilytype of the interface to load
Returns:
the interface object if found and loaded, NULL otherwise.

Closes an interface

Parameters:
interface_objthe 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_objthe interface object used
secNamethe desired key parent section name
keyNamethe 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_objthe interface object used
secNamethe desired key parent section name
keyNamethe desired key name
keyValuethe 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_objthe interface object used
Returns:
handle to the config file