gst.registry

Module for [Registry] class

class Registry RegistryGidBuilder RegistryGidBuilderImpl

Types 3

One registry holds the metadata of a set of plugins.

<emphasis role="bold">Design:</emphasis>

The #GstRegistry object is a list of plugins and some functions for dealing with them. Each #GstPlugin is matched 1-1 with a file on disk, and may or may not be loaded at a given time.

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.

Implementation notes:

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.types.PluginFlags.Cached] bit. These plugins are removed at the end of initialization.

Methods

GType _getGType()

GType _gType() @property

Registry self()Returns `this`, for use in `with` statements.

RegistryGidBuilder builder()Get builder for [gst.registry.Registry] Returns: New builder object

bool forkIsEnabled()By default GStreamer will perform scanning and rebuilding of the registry file using a helper child process.

void forkSetEnabled(bool enabled)Applications might want to disable/enable spawning of a child helper process when rebuilding the registry. See [gst.registry.Registry.forkIsEnabled] for more information.

gst.registry.Registry get()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. Returns: the #GstRegistry.

bool addFeature(gst.plugin_feature.PluginFeature feature)Add the feature to the registry. The feature-added signal will be emitted.

bool addPlugin(gst.plugin.Plugin plugin)Add the plugin to the registry. The plugin-added signal will be emitted.

bool checkFeatureVersion(string featureName, uint minMajor, uint minMinor, uint minMicro)Checks whether a plugin feature by the given name exists in registry and whether its version is at least the version required.

gst.plugin_feature.PluginFeature[] featureFilter(gst.types.PluginFeatureFilter filter, bool first)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).

gst.plugin_feature.PluginFeature findFeature(string name, gobject.types.GType type)Find the pluginfeature with the given name and type in the registry.

gst.plugin.Plugin findPlugin(string name)Find the plugin with the given name in the registry. The plugin will be reffed; caller is responsible for unreffing.

gst.plugin_feature.PluginFeature[] getFeatureList(gobject.types.GType type)Retrieves a #GList of #GstPluginFeature of type.

gst.plugin_feature.PluginFeature[] getFeatureListByPlugin(string name)Retrieves a #GList of features of the plugin with name name.

uint getFeatureListCookie()Returns the registry's feature list cookie. This changes every time a feature is added or removed from the registry. Returns: the feature list cookie.

gst.plugin.Plugin[] getPluginList()Get a copy of all plugins registered in the given registry. The refcount of each element in the list in incremented. Returns: a #GList of #GstPlugin. Use [gst.plugin.Plugin.listFree] after usage.

gst.plugin.Plugin lookup(string filename)Look up a plugin in the given registry with the given filename. If found, plugin is reffed.

gst.plugin_feature.PluginFeature lookupFeature(string name)Find a #GstPluginFeature with name in registry.

gst.plugin.Plugin[] pluginFilter(gst.types.PluginFilter filter, bool first)Runs a filter against all 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). Every plugin is...

void removeFeature(gst.plugin_feature.PluginFeature feature)Remove the feature from the registry.

void removePlugin(gst.plugin.Plugin plugin)Remove the plugin from the registry.

bool scanPath(string path)Scan the given path for plugins to add to the registry. The syntax of the path is specific to the registry.

gulong connectFeatureAdded(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0] :  gst.plugin_feature.PluginFeature)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gst.registry.Registry)))
   &&  Parameters!T.length <  3)

Connect to `FeatureAdded` signal.

gulong connectPluginAdded(T)(T callback,  Flag!"After" after =  No.After) if (isCallable!T
    &&  is(ReturnType!T ==  void)
   && (Parameters!T.length <  1 || (ParameterStorageClassTuple!T[0]  ==  ParameterStorageClass.none &&  is(Parameters!T[0] :  gst.plugin.Plugin)))
   && (Parameters!T.length <  2 || (ParameterStorageClassTuple!T[1]  ==  ParameterStorageClass.none &&  is(Parameters!T[1] :  gst.registry.Registry)))
   &&  Parameters!T.length <  3)

Connect to `PluginAdded` signal.

Constructors

this(void * ptr, Flag!"Take" take)

classRegistryGidBuilderImpl(T) : gst.object.ObjectWrapGidBuilderImpl!T

classRegistryGidBuilder : RegistryGidBuilderImpl!RegistryGidBuilder

Fluent builder for [gst.registry.Registry]

Methods

Registry build()