One registry holds the metadata of a set of plugins.
The primary source, at all times, of plugin information is each plugin file itself. Thus, if an application wants information about a particular plugin, or wants to search for a feature that satisfies given criteria, the primary means of doing so is to load every plugin and look at the resulting information that is gathered in the default registry. Clearly, this is a time consuming process, so we cache information in the registry file. The format and location of the cache file is internal to gstreamer.
On startup, plugins are searched for in the plugin search path. The following locations are checked in this order:
* location from --gst-plugin-path commandline option. * the GST_PLUGIN_PATH environment variable. * the GST_PLUGIN_SYSTEM_PATH environment variable. * default locations (if GST_PLUGIN_SYSTEM_PATH is not set). Those default locations are: $XDG_DATA_HOME/gstreamer-$GST_API_VERSION/plugins/ and $prefix/libs/gstreamer-$GST_API_VERSION/. $XDG_DATA_HOME defaults to $HOME/.local/share.
The registry cache file is loaded from $XDG_CACHE_HOME/gstreamer-$GST_API_VERSION/registry-$ARCH.bin (where $XDG_CACHE_HOME defaults to $HOME/.cache) or the file listed in the GST_REGISTRY env var. One reason to change the registry location is for testing.
For each plugin that is found in the plugin search path, there could be 3 possibilities for cached information:
* the cache may not contain information about a given file. * the cache may have stale information. * the cache may have current information.
In the first two cases, the plugin is loaded and the cache updated. In addition to these cases, the cache may have entries for plugins that are not relevant to the current process. These are marked as not available to the current process. If the cache is updated for whatever reason, it is marked dirty.
A dirty cache is written out at the end of initialization. Each entry is checked to make sure the information is minimally valid. If not, the entry is simply dropped.
The "cache" and "registry" are different concepts and can represent different sets of plugins. For various reasons, at init time, the cache is stored in the default registry, and plugins not relevant to the current process are marked with the GST_PLUGIN_FLAG_CACHED bit. These plugins are removed at the end of initialization.
Sets our main struct and passes it to the parent class.
Add the feature to the registry. The feature-added signal will be emitted.
Signals that a feature has been added to the registry (possibly replacing a previously-added one by the same name)
Signals that a plugin has been added to the registry (possibly replacing a previously-added one by the same name)
Add the plugin to the registry. The plugin-added signal will be emitted.
Checks whether a plugin feature by the given name exists in registry and whether its version is at least the version required.
Runs a filter against all features of the plugins in the registry and returns a GList with the results. If the first flag is set, only the first match is returned (as a list with a single object).
Find the pluginfeature with the given name and type in the registry.
Find the plugin with the given name in the registry. The plugin will be reffed; caller is responsible for unreffing.
Retrieves a GList of features of the plugin with name name.
Returns the registry's feature list cookie. This changes every time a feature is added or removed from the registry.
Get a copy of all plugins registered in the given registry. The refcount of each element in the list in incremented.
Get the main Gtk struct
the main Gtk struct as a void*
Look up a plugin in the given registry with the given filename. If found, plugin is reffed.
Find a gstreamer.PluginFeature with name in registry.
Remove the feature from the registry.
Remove the plugin from the registry.
Scan the given path for plugins to add to the registry. The syntax of the path is specific to the registry.
By default GStreamer will perform scanning and rebuilding of the registry file using a helper child process.
Applications might want to disable/enable spawning of a child helper process when rebuilding the registry. See Registry.forkIsEnabled for more information.
Retrieves the singleton plugin registry. The caller does not own a reference on the registry, as it is alive as long as GStreamer is initialized.
the main Gtk struct
the main Gtk struct
Get the main Gtk struct
the main Gtk struct as a void*
Checks to see if there is any object named name in list. This function does not do any locking of any kind. You might want to protect the provided list with the lock of the owner of the list. This function will lock each GstObject in the list to compare the name, so be careful when passing a list with a locked object.
A default deep_notify signal callback for an object. The user data should contain a pointer to an array of strings that should be excluded from the notify. The default handler will print the new value of the property using g_print.
Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference.
Atomically modifies a pointer to point to a new object. The reference count of oldobj is decreased and the reference count of newobj is increased.
A default error function that uses g_printerr() to display the error message and the optional debug sting..
Gets the corresponding gstreamer.ControlBinding for the property. This should be unreferenced again after use.
Obtain the control-rate for this object. Audio processing gstreamer.Element objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() inbetween. The length of the processing segment should be up to control-rate nanoseconds.
Returns a copy of the name of object. Caller should g_free() the return value after usage. For a nameless object, this returns NULL, which you can safely g_free() as well.
Returns the parent of object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.
Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.
Gets the value for the given controlled property at the requested time.
Gets a number of values for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of the same type as the objects property's type.
Check if the object has active controlled properties.
Increments the reference count on object. This function does not take the lock on object because it relies on atomic refcounting.
Removes the corresponding gstreamer.ControlBinding If it was the last ref of the binding, it will be disposed.
This function is used to disable the control bindings on a property for some time, i.e. gst_object_sync_values() will do nothing for the property.
This function is used to disable all controlled properties of the object for some time, i.e. gst_object_sync_values() will do nothing.
Change the control-rate for this object. Audio processing gstreamer.Element objects will use this rate to sub-divide their processing loop and call gst_object_sync_values() inbetween. The length of the processing segment should be up to control-rate nanoseconds.
Sets the name of object, or gives object a guaranteed unique name (if name is NULL). This function makes a copy of the provided name, so the caller retains ownership of the name it sent.
Sets the parent of object to parent. The object's reference count will be incremented, and any floating reference will be removed (see gst_object_ref_sink()).
Returns a suggestion for timestamps where buffers should be split to get best controller results.
Sets the properties of the object, according to the gstreamer.ControlSources that (maybe) handle them and for the given timestamp.
Clear the parent of object, removing the associated reference. This function decreases the refcount of object.
Decrements the reference count on object. If reference count hits zero, destroy object. This function does not take the lock on object as it relies on atomic refcounting.
The deep notify signal is used to be notified of property changes. It is typically attached to the toplevel bin to receive notifications from all the elements contained in that bin.