ControlSource

The gstreamer.ControlSource is a base class for control value sources that could be used to get timestamp-value pairs. A control source essentially is a function over time.

A gstreamer.ControlSource is used by first getting an instance of a specific control-source, creating a binding for the control-source to the target property of the element and then adding the binding to the element. The binding will convert the data types and value range to fit to the bound property.

For implementing a new gstreamer.ControlSource one has to implement GstControlSourceGetValue and GstControlSourceGetValueArray functions. These are then used by ControlSource.getValue and ControlSource.getValueArray to get values for specific timestamps.

class ControlSource : ObjectGst {

protected

GstControlSource* gstControlSource;

GstControlSource* getControlSourceStruct(bool transferOwnership);

void* getStruct();

this(GstControlSource* gstControlSource, bool ownedRef);

static GType getType();

bool getValue(GstClockTime timestamp, double value);

bool getValueArray(GstClockTime timestamp, GstClockTime interval, double[] values);

}

Constructors

this this(GstControlSource* gstControlSource, bool ownedRef): Sets our main struct and passes it to the parent class.

Members

Functions

getControlSourceStruct GstControlSource* getControlSourceStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getValue bool getValue(GstClockTime timestamp, double value): Gets the value for this gstreamer.ControlSource at a given timestamp.
getValueArray bool getValueArray(GstClockTime timestamp, GstClockTime interval, double[] values): Gets an array of values for for this gstreamer.ControlSource Values that are undefined contain NANs.

Static functions

getType GType getType()

Variables

gstControlSource GstControlSource* gstControlSource;: the main Gtk struct

Inherited Members

From ObjectGst

gstObject GstObject* gstObject;: the main Gtk struct
getObjectGstStruct GstObject* getObjectGstStruct(bool transferOwnership): Get the main Gtk struct
getStruct void* getStruct(): the main Gtk struct as a void*
getType GType getType()
checkUniqueness bool 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 careful when passing a list with a locked object.
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.
refSink void* refSink(void* object): Increase the reference count of object, and possibly remove the floating reference, if object has a floating reference.
replace bool 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.
addControlBinding bool addControlBinding(ControlBinding binding): Attach the gstreamer.ControlBinding to the object. If there already was a gstreamer.ControlBinding for this property it will be replaced.
defaultError void defaultError(ErrorG error, string debug_): A default error function that uses g_printerr() to display the error message and the optional debug string..
getControlBinding ControlBinding getControlBinding(string propertyName): Gets the corresponding gstreamer.ControlBinding for the property. This should be unreferenced again after use.
getControlRate GstClockTime getControlRate(): 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() in between. The length of the processing segment should be up to control-rate nanoseconds.
getGValueArray bool getGValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, Value[] values): Gets a number of gobject.Values for the given controlled property starting at the requested time. The array values need to hold enough space for n_values of gobject.Value
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.
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.
getPathString string getPathString(): Generates a string describing the path of object in the object hierarchy. Only useful (or used) for debugging.
getValue Value getValue(string propertyName, GstClockTime timestamp): Gets the value for the given controlled property at the requested time.
getValueArray bool getValueArray(string propertyName, GstClockTime timestamp, GstClockTime interval, uint nValues, 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.
hasActiveControlBindings bool hasActiveControlBindings(): Check if the object has active controlled properties.
hasAncestor bool hasAncestor(ObjectGst ancestor): Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a gstreamer.Element is inside a gstreamer.Pipeline
hasAsAncestor bool hasAsAncestor(ObjectGst ancestor): Check if object has an ancestor ancestor somewhere up in the hierarchy. One can e.g. check if a gstreamer.Element is inside a gstreamer.Pipeline
hasAsParent bool hasAsParent(ObjectGst parent): Check if parent is the parent of object. E.g. a gstreamer.Element can check if it owns a given gstreamer.Pad
ref_ ObjectGst ref_(): Increments the reference count on object. This function does not take the lock on object because it relies on atomic refcounting.
removeControlBinding bool removeControlBinding(ControlBinding binding): Removes the corresponding gstreamer.ControlBinding If it was the last ref of the binding, it will be disposed.
setControlBindingDisabled void setControlBindingDisabled(string propertyName, bool disabled): 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.
setControlBindingsDisabled void setControlBindingsDisabled(bool 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.
setControlRate void setControlRate(GstClockTime controlRate): 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() in between. The length of the processing segment should be up to control-rate nanoseconds.
setName bool 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.
setParent bool 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()).
suggestNextSync GstClockTime suggestNextSync(): Returns a suggestion for timestamps where buffers should be split to get best controller results.
syncValues bool syncValues(GstClockTime timestamp): Sets the properties of the object, according to the gstreamer.ControlSources that (maybe) handle them and for the given timestamp.
unparent void unparent(): Clear the parent of object, removing the associated reference. This function decreases the refcount of object.
unref void unref(): 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.
addOnDeepNotify gulong 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.

gstreamer ControlSource classes

ControlSource