Gst::Plugin Class Reference

Gst::Plugin - Container for features loaded from a shared object module. More...

#include <plugin.h>

Inheritance diagram for Gst::Plugin:

Gst::Object

List of all members.

Public Types

typedef sigc::slot< bool,
const Glib::RefPtr
<Gst::Plugin >&> 
SlotInit
 For example, bool on_plugin_init(const Glib::RefPtr<Gst::Plugin>& plugin);.
typedef sigc::slot< bool,
const Glib::RefPtr
<Gst::Plugin >&> 
SlotFilter
 For example, bool on_plugin_filter(const Glib::RefPtr<Gst::Plugin>& plugin);.

Public Member Functions

virtual ~Plugin ()
GstPlugin* gobj ()
 Provides access to the underlying C GObject.
const GstPlugin* gobj () const
 Provides access to the underlying C GObject.
GstPlugin* gobj_copy ()
 Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.
Glib::ustring get_name () const
 Get the short name of the plugin.
Glib::ustring get_description () const
 Get the long descriptive name of the plugin.
Glib::ustring get_filename () const
 get the filename of the plugin
Glib::ustring get_license () const
 get the license of the plugin
Glib::ustring get_package () const
 get the package the plugin belongs to.
Glib::ustring get_origin () const
 get the URL where the plugin comes from
Glib::ustring get_source () const
 get the source module the plugin belongs to.
Glib::ustring get_version () const
 get the version of the plugin
GModule* get_module ()
 Gets the Module of the plugin.
const GModule* get_module () const
 Gets the Module of the plugin.
bool is_loaded () const
 queries if the plugin is loaded into memory
const Gst::Structure get_cache_data () const
 Gets the plugin specific data cache.
void set_cache_data (Gst::Structure& cache_data)
 Adds plugin specific data to cache.
Glib::RefPtr<Gst::Pluginload ()
 Loads plugin.
bool register_static (int major_version, int minor_version, const Glib::ustring& name, const Glib::ustring& description, const SlotInit& init_slot, const Glib::ustring& version, const Glib::ustring& license, const Glib::ustring& source, const Glib::ustring& package, const Glib::ustring& origin)
void add_dependency (const Glib::StringArrayHandle& env_vars, const Glib::StringArrayHandle& paths, const Glib::StringArrayHandle& names, Gst::PluginDependencyFlags flags)
 Make GStreamer aware of external dependencies which affect the feature set of this plugin (ie.
void add_dependency (const Glib::ustring& env_vars, const Glib::ustring& paths, const Glib::ustring& names, Gst::PluginDependencyFlags flags)
 Make GStreamer aware of external dependencies which affect the feature set of this plugin (ie.

Static Public Member Functions

static Glib::QueryQuark error_quark ()
static Glib::RefPtr<Gst::Pluginload_file (const Glib::ustring& filename)
 Loads a plugin from file.
static Glib::RefPtr<Gst::Pluginload_by_name (const Glib::ustring& name)
 Load the named plugin.

Related Functions

(Note that these are not member functions.)

Glib::RefPtr<Gst::Pluginwrap (GstPlugin* object, bool take_copy=false)
 A Glib::wrap() method for this object.


Detailed Description

Gst::Plugin - Container for features loaded from a shared object module.

GStreamer is extensible, so Gst::Element instances can be loaded at runtime. A plugin system can provide one or more of the basic GStreamer Gst::PluginFeature subclasses.

TODO: Edit following paragraph to use gstreamermm classes/methods:

A plugin should export a symbol gst_plugin_desc that is a struct of type PluginDesc. the plugin loader will check the version of the core library the plugin was linked against and will create a new Gst::Plugin. It will then call the PluginInitFunc function that was provided in the gst_plugin_desc.

Once you have a handle to a Gst::Plugin (e.g. from the RegistryPool), you can add any object that subclasses Gst::PluginFeature.

Usually plugins are always automaticlly loaded so you don't need to call gst_plugin_load() explicitly to bring it into memory. There are options to statically link plugins to an app or even use GStreamer without a plugin repository in which case load() can be needed to bring the plugin into memory.


Member Typedef Documentation

typedef sigc::slot<bool, const Glib::RefPtr<Gst::Plugin>&> Gst::Plugin::SlotFilter

For example, bool on_plugin_filter(const Glib::RefPtr<Gst::Plugin>& plugin);.

The filter function should return true if plugin is a match, false otherwise.

typedef sigc::slot<bool, const Glib::RefPtr<Gst::Plugin>&> Gst::Plugin::SlotInit

For example, bool on_plugin_init(const Glib::RefPtr<Gst::Plugin>& plugin);.

The init function should return true if plugin was initialized successfully, false otherwise.


Constructor & Destructor Documentation

virtual Gst::Plugin::~Plugin (  )  [virtual]


Member Function Documentation

void Gst::Plugin::add_dependency ( const Glib::ustring &  env_vars,
const Glib::ustring &  paths,
const Glib::ustring &  names,
Gst::PluginDependencyFlags  flags 
)

Make GStreamer aware of external dependencies which affect the feature set of this plugin (ie.

the elements or typefinders associated with it).

GStreamer will re-inspect plugins with external dependencies whenever any of the external dependencies change. This is useful for plugins which wrap other plugin systems, e.g. a plugin which wraps a plugin-based visualisation library and makes visualisations available as GStreamer elements, or a codec loader which exposes elements and/or caps dependent on what external codec libraries are currently installed.

Convenience wrapper function for add_dependency() which takes simple strings as arguments instead of string arrays, with multiple arguments separated by predefined delimiters (see above).

Since: 0.10.22

Parameters:
env_vars One or more environent variables (separated by ':', ';' or ','), or 0. Environment variable names may be followed by a path component which will be added to the content of the environment variable, e.g. "HOME/.mystuff/plugins:MYSTUFF_PLUGINS_PATH".
paths One ore more directory paths (separated by ':' or ';' or ','), or 0. Example: "/usr/lib/mystuff/plugins".
names One or more file names or file name suffixes (separated by commas), or 0.
flags Optional flags, or Gst::PLUGIN_DEPENDENCY_FLAG_NONE.

void Gst::Plugin::add_dependency ( const Glib::StringArrayHandle &  env_vars,
const Glib::StringArrayHandle &  paths,
const Glib::StringArrayHandle &  names,
Gst::PluginDependencyFlags  flags 
)

Make GStreamer aware of external dependencies which affect the feature set of this plugin (ie.

the elements or typefinders associated with it).

GStreamer will re-inspect plugins with external dependencies whenever any of the external dependencies change. This is useful for plugins which wrap other plugin systems, e.g. a plugin which wraps a plugin-based visualisation library and makes visualisations available as GStreamer elements, or a codec loader which exposes elements and/or caps dependent on what external codec libraries are currently installed.

Since: 0.10.22

Parameters:
env_vars 0-terminated array of environent variables affecting the feature set of the plugin (e.g. an environment variable containing paths where to look for additional modules/plugins of a library), or 0. Environment variable names may be followed by a path component which will be added to the content of the environment variable, e.g. "HOME/.mystuff/plugins".
paths 0-terminated array of directories/paths where dependent files may be.
names 0-terminated array of file names (or file name suffixes, depending on flags) to be used in combination with the paths from paths and/or the paths extracted from the environment variables in env_vars, or 0.
flags Optional flags, or Gst::PLUGIN_DEPENDENCY_FLAG_NONE.

static Glib::QueryQuark Gst::Plugin::error_quark (  )  [static]

const Gst::Structure Gst::Plugin::get_cache_data (  )  const

Gets the plugin specific data cache.

If it is 0 there is no cached data stored. This is the case when the registry is getting rebuild.

Returns:
The cached data as a Gst::Structure or 0.
Since: 0.10.24.

Glib::ustring Gst::Plugin::get_description (  )  const

Get the long descriptive name of the plugin.

Returns:
The long name of the plugin.

Glib::ustring Gst::Plugin::get_filename (  )  const

get the filename of the plugin

Returns:
The filename of the plugin.

Glib::ustring Gst::Plugin::get_license (  )  const

get the license of the plugin

Returns:
The license of the plugin.

const GModule* Gst::Plugin::get_module (  )  const

Gets the Module of the plugin.

If the plugin isn't loaded yet, 0 is returned.

Returns:
Module belonging to the plugin or 0 if the plugin isn't loaded yet.

GModule* Gst::Plugin::get_module (  ) 

Gets the Module of the plugin.

If the plugin isn't loaded yet, 0 is returned.

Returns:
Module belonging to the plugin or 0 if the plugin isn't loaded yet.

Glib::ustring Gst::Plugin::get_name (  )  const

Get the short name of the plugin.

Returns:
The name of the plugin.

Reimplemented from Gst::Object.

Glib::ustring Gst::Plugin::get_origin (  )  const

get the URL where the plugin comes from

Returns:
The origin of the plugin.

Glib::ustring Gst::Plugin::get_package (  )  const

get the package the plugin belongs to.

Returns:
The package of the plugin.

Glib::ustring Gst::Plugin::get_source (  )  const

get the source module the plugin belongs to.

Returns:
The source of the plugin.

Glib::ustring Gst::Plugin::get_version (  )  const

get the version of the plugin

Returns:
The version of the plugin.

const GstPlugin* Gst::Plugin::gobj (  )  const [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Object.

GstPlugin* Gst::Plugin::gobj (  )  [inline]

Provides access to the underlying C GObject.

Reimplemented from Gst::Object.

GstPlugin* Gst::Plugin::gobj_copy (  ) 

Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs.

Reimplemented from Gst::Object.

bool Gst::Plugin::is_loaded (  )  const

queries if the plugin is loaded into memory

Returns:
true is loaded, false otherwise.

Glib::RefPtr<Gst::Plugin> Gst::Plugin::load (  ) 

Loads plugin.

Note that the *return value* is the loaded plugin; plugin is untouched. The normal use pattern of this function goes like this:

<programlisting> GstPlugin *loaded_plugin; loaded_plugin = gst_plugin_load (plugin); // presumably, we're no longer interested in the potentially-unloaded plugin gst_object_unref (plugin); plugin = loaded_plugin; </programlisting>

Returns:
A reference to a loaded plugin, or 0 on error.

static Glib::RefPtr<Gst::Plugin> Gst::Plugin::load_by_name ( const Glib::ustring &  name  )  [static]

Load the named plugin.

Refs the plugin.

Parameters:
name Name of plugin to load.
Returns:
A reference to a loaded plugin, or 0 on error.

static Glib::RefPtr<Gst::Plugin> Gst::Plugin::load_file ( const Glib::ustring &  filename  )  [static]

Loads a plugin from file.

Exceptions:
Gst::PluginError. 
Parameters:
filename The plugin filename to load.
Returns:
A reference to the existing loaded GstPlugin, a reference to the newly-loaded GstPlugin, or 0 if an error occurred.

bool Gst::Plugin::register_static ( int  major_version,
int  minor_version,
const Glib::ustring &  name,
const Glib::ustring &  description,
const SlotInit init_slot,
const Glib::ustring &  version,
const Glib::ustring &  license,
const Glib::ustring &  source,
const Glib::ustring &  package,
const Glib::ustring &  origin 
)

void Gst::Plugin::set_cache_data ( Gst::Structure cache_data  ) 

Adds plugin specific data to cache.

Passes the ownership of the structure to the plugin.

The cache is flushed every time the registry is rebuild.

Since: 0.10.24

Parameters:
cache_data A structure containing the data to cache.


Friends And Related Function Documentation

Glib::RefPtr<Gst::Plugin> wrap ( GstPlugin *  object,
bool  take_copy = false 
) [related]

A Glib::wrap() method for this object.

Parameters:
object The C instance.
take_copy False if the result should take ownership of the C instance. True if it should take a new copy or ref.
Returns:
A C++ instance that wraps this C instance.


The documentation for this class was generated from the following file:

Generated on Wed Aug 19 17:19:20 2009 for gstreamermm by  doxygen 1.5.9