# Gst::Plugin Class Reference

A container for features loaded from a shared object module. More...

Inherits Gst::Object.

Collaboration diagram for Gst::Plugin:
[legend]

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::Plugin > | load ()
| 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::Plugin > | load_file (const Glib::ustring& filename)
static Glib::RefPtr< Gst::Plugin > | load_by_name (const Glib::ustring& name)
| Load the named plugin.

## Related Functions

(Note that these are not member functions.)
Glib::RefPtr< Gst::Plugin > | wrap (GstPlugin* object, bool take_copy=false)
| A Glib::wrap() method for this object.

## Detailed Description

A 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::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 gstreamermm 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.

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 gstreamermm 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.

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 rebuilt.

Since gstreamermm 0.10:
  .24

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

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.

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.

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.

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]`

Exceptions:

  | Gst::PluginError. |

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 rebuilt.

Since gstreamermm 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:

- gstreamermm/plugin.h