Plugin

GStreamer is extensible, so GstElement instances can be loaded at runtime. A plugin system can provide one or more of the basic GStreamer GstPluginFeature subclasses.

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

Once you have a handle to a GstPlugin (e.g. from the GstRegistry), you can add any object that subclasses GstPluginFeature.

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 gst_plugin_load() can be needed to bring the plugin into memory.

class Plugin : ObjectGst {

protected

GstPlugin* gstPlugin;

GstPlugin* getPluginStruct();

void* getStruct();

this(GstPlugin* gstPlugin);

void setStruct(GObject* obj);

static GQuark errorQuark();

string getName();

string getDescription();

string getFilename();

string getLicense();

string getPackage();

string getOrigin();

string getSource();

string getVersion();

string getReleaseDateString();

int isLoaded();

Structure getCacheData();

void setCacheData(Structure cacheData);

static Plugin loadFile(string filename);

Plugin load();

static Plugin loadByName(string name);

static void listFree(ListG list);

static int registerStatic(int majorVersion, int minorVersion, string name, string description, GstPluginInitFunc initFunc, string versio, string license, string source, string p, string origin);

static int registerStaticFull(int majorVersion, int minorVersion, string name, string description, GstPluginInitFullFunc initFullFunc, string versio, string license, string source, string p, string origin, void* userData);

void addDependency(string[] envVars, string[] paths, string[] names, GstPluginDependencyFlags flags);

void addDependencySimple(string envVars, string paths, string names, GstPluginDependencyFlags flags);

}

Constructors

this this(GstPlugin* gstPlugin): Sets our main struct and passes it to the parent class

Members

Functions

addDependency void addDependency(string[] envVars, string[] paths, string[] names, GstPluginDependencyFlags 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.
addDependencySimple void addDependencySimple(string envVars, string paths, string names, GstPluginDependencyFlags 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 gst_plugin_add_dependency() which takes simple strings as arguments instead of string arrays, with multiple arguments separated by predefined delimiters (see above).
getCacheData Structure getCacheData(): Gets the plugin specific data cache. If it is NULL there is no cached data stored. This is the case when the registry is getting rebuilt.
getDescription string getDescription(): Get the long descriptive name of the plugin
getFilename string getFilename(): get the filename of the plugin
getLicense string getLicense(): get the license of the plugin
getName string getName(): Get the short name of the plugin
getOrigin string getOrigin(): get the URL where the plugin comes from
getPackage string getPackage(): get the package the plugin belongs to.
getPluginStruct GstPlugin* getPluginStruct(): Undocumented in source. Be warned that the author may not have intended to support it.
getReleaseDateString string getReleaseDateString(): Get the release date (and possibly time) in form of a string, if available. For normal GStreamer plugin releases this will usually just be a date in the form of "YYYY-MM-DD", while pre-releases and builds from git may contain a time component after the date as well, in which case the string will be formatted like "YYYY-MM-DDTHH:MMZ" (e.g. "2012-04-30T09:30Z"). There may be plugins that do not have a valid release date set on them.
getSource string getSource(): get the source module the plugin belongs to.
getStruct void* getStruct(): the main Gtk struct as a void*
getVersion string getVersion(): get the version of the plugin
isLoaded int isLoaded(): queries if the plugin is loaded into memory
load Plugin load(): Loads plugin. Note that the *return value* is the loaded plugin; plugin is
setCacheData void setCacheData(Structure cacheData): 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.
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.

Static functions

errorQuark GQuark errorQuark(): Get the error quark.
listFree void listFree(ListG list): Unrefs each member of list, then frees the list.
loadByName Plugin loadByName(string name): Load the named plugin. Refs the plugin.
loadFile Plugin loadFile(string filename): Loads the given plugin and refs it. Caller needs to unref after use.
registerStatic int registerStatic(int majorVersion, int minorVersion, string name, string description, GstPluginInitFunc initFunc, string versio, string license, string source, string p, string origin): Registers a static plugin, ie. a plugin which is private to an application or library and contained within the application or library (as opposed to being shipped as a separate module file). You must make sure that GStreamer has been initialised (with gst_init() or via gst_init_get_option_group()) before calling this function.
registerStaticFull int registerStaticFull(int majorVersion, int minorVersion, string name, string description, GstPluginInitFullFunc initFullFunc, string versio, string license, string source, string p, string origin, void* userData): Registers a static plugin, ie. a plugin which is private to an application or library and contained within the application or library (as opposed to being shipped as a separate module file) with a GstPluginInitFullFunc which allows user data to be passed to the callback function (useful for bindings). You must make sure that GStreamer has been initialised (with gst_init() or via gst_init_get_option_group()) before calling this function.

Variables

gstPlugin GstPlugin* gstPlugin;: the main Gtk struct

Inherited Members

From ObjectGst

gstObject GstObject* gstObject;: the main Gtk struct
getObjectGstStruct GstObject* getObjectGstStruct(): Undocumented in source. Be warned that the author may not have intended to support it.
getStruct void* getStruct(): the main Gtk struct as a void*
setStruct void setStruct(GObject* obj): Undocumented in source. Be warned that the author may not have intended to support it.
connectedSignals int[string] connectedSignals;
onDeepNotifyListeners void delegate(ObjectGst, ParamSpec, ObjectGst)[] onDeepNotifyListeners;: Undocumented in source.
addOnDeepNotify void addOnDeepNotify(void delegate(ObjectGst, ParamSpec, ObjectGst) dlg, ConnectFlags connectFlags): 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.
callBackDeepNotify void callBackDeepNotify(GstObject* gstobjectStruct, GstObject* propObject, GParamSpec* prop, ObjectGst _objectGst): Undocumented in source. Be warned that the author may not have intended to support it.
setName int setName(string name): 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.
getName string getName(): 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. Free-function: g_free
setParent int setParent(ObjectGst parent): 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()).
getParent ObjectGst getParent(): Returns the parent of object. This function increases the refcount of the parent object so you should gst_object_unref() it after usage.
unparent void unparent(): Clear the parent of object, removing the associated reference. This function decreases the refcount of object. MT safe. Grabs and releases object's lock.
defaultDeepNotify void defaultDeepNotify(ObjectG object, ObjectGst orig, ParamSpec pspec, string[] excludedProps): 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. MT safe. This function grabs and releases object's LOCK for getting its path string.
defaultError void defaultError(ErrorG error, char dbug): A default error function that uses g_printerr() to display the error message and the optional debug sting.. The default handler will simply print the error string using g_print.
checkUniqueness int checkUniqueness(ListG list, string name): 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 carefull when passing a list with a locked object.
hasAncestor int hasAncestor(ObjectGst ancestor): Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a GstElement is inside a GstPipeline.
doref void* doref(void* object): Increments the reference count on object. This function does not take the lock on object because it relies on atomic refcounting. This object returns the input parameter to ease writing
unref void unref(void* 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 unref method should never be called with the LOCK held since this might deadlock the dispose function.
refSink void* refSink(void* object): Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference. In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.
replace int replace(ObjectGst oldobj, ObjectGst newobj): 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. Either newobj and the value pointed to by oldobj may be NULL.
getPathString string getPathString(): Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging. Free-function: g_free
suggestNextSync GstClockTime suggestNextSync(): Returns a suggestion for timestamps where buffers should be split to get best controller results.
syncValues int syncValues(GstClockTime timestamp): Sets the properties of the object, according to the GstControlSources that (maybe) handle them and for the given timestamp. If this function fails, it is most likely the application developers fault. Most probably the control sources are not setup correctly.
hasActiveControlBindings int hasActiveControlBindings(): Check if the object has an active controlled properties.
setControlBindingsDisabled void setControlBindingsDisabled(int disabled): This function is used to disable all controlled properties of the object for some time, i.e. gst_object_sync_values() will do nothing.
setControlBindingDisabled void setControlBindingDisabled(string propertyName, int disabled): This function is used to disable the GstController on a property for some time, i.e. gst_controller_sync_values() will do nothing for the property.
addControlBinding int addControlBinding(ControlBinding binding): Attach the GstControlBinding to the object. If there already was a GstControlBinding for this property it will be replaced. The object will take ownership of the binding.
getControlBinding ControlBinding getControlBinding(string propertyName): Gets the corresponding GstControlBinding for the property. This should be unreferenced again after use.
removeControlBinding int removeControlBinding(ControlBinding binding): Removes the corresponding GstControlBinding. If it was the last ref of the binding, it will be disposed.
getValue Value getValue(string propertyName, GstClockTime timestamp): Gets the value for the given controlled property at the requested time.
getValueArray int getValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, void[] values): 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. This function is useful if one wants to e.g. draw a graph of the control curve or apply a control curve sample by sample. The values are unboxed and ready to be used. The similar function gst_object_get_g_value_array() returns the array as GValues and is better suites for bindings.
getGValueArray int getGValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, uint nValues, Value values): Gets a number of GValues for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of GValue. This function is useful if one wants to e.g. draw a graph of the control curve or apply a control curve sample by sample.
getControlRate GstClockTime getControlRate(): Obtain the control-rate for this object. Audio processing GstElement 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. If the object is not under property control, this will return GST_CLOCK_TIME_NONE. This allows the element to avoid the sub-dividing. The control-rate is not expected to change if the element is in GST_STATE_PAUSED or GST_STATE_PLAYING.
setControlRate void setControlRate(GstClockTime controlRate): Change the control-rate for this object. Audio processing GstElement 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. The control-rate should not change if the element is in GST_STATE_PAUSED or GST_STATE_PLAYING.