GstControlSource

The GstControlSource 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 GstControlSource 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 GstControlSource one has to implement GstControlSourceGetValue and GstControlSourceGetValueArray functions. These are then used by gst_control_source_get_value and gst_control_source_get_value_array to get values for specific timestamps.

GstControlSource

GObject
    ╰──GInitiallyUnowned
        ╰──GstObject
            ╰──GstControlSource

The instance structure of GstControlSource.

Members

parent (GstObject) –

the parent structure

get_value (GstControlSourceGetValue) –

Function for returning a value for a given timestamp

get_value_array (GstControlSourceGetValueArray) –

Function for returning a values array for a given timestamp

Class structure

GstControlSourceClass

The class structure of GstControlSource.

Fields

parent_class (GstObjectClass) –

Parent class

Gst.ControlSourceClass

The class structure of Gst.ControlSource.

Attributes

parent_class (Gst.ObjectClass) –

Parent class

Gst.ControlSourceClass

The class structure of Gst.ControlSource.

Attributes

parent_class (Gst.ObjectClass) –

Parent class

Gst.ControlSource

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.ControlSource

The instance structure of Gst.ControlSource.

Members

parent (Gst.Object) –

the parent structure

get_value (Gst.ControlSourceGetValue) –

Function for returning a value for a given timestamp

get_value_array (Gst.ControlSourceGetValueArray) –

Function for returning a values array for a given timestamp

Gst.ControlSource

GObject.Object
    ╰──GObject.InitiallyUnowned
        ╰──Gst.Object
            ╰──Gst.ControlSource

The instance structure of Gst.ControlSource.

Members

parent (Gst.Object) –

the parent structure

get_value (Gst.ControlSourceGetValue) –

Function for returning a value for a given timestamp

get_value_array (Gst.ControlSourceGetValueArray) –

Function for returning a values array for a given timestamp

Methods

gst_control_source_get_value

gboolean
gst_control_source_get_value (GstControlSource * self,
                              GstClockTime timestamp,
                              gdouble * value)

Gets the value for this GstControlSource at a given timestamp.

Parameters:

self –

the GstControlSource object

timestamp –

the time for which the value should be returned

value ( [out]) –

the value

Returns –

FALSE if the value couldn't be returned, TRUE otherwise.

Gst.ControlSource.prototype.control_source_get_value

function Gst.ControlSource.prototype.control_source_get_value(timestamp: Number): {
    // javascript wrapper for 'gst_control_source_get_value'
}

Gets the value for this Gst.ControlSource at a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource object

timestamp (Number) –

the time for which the value should be returned

Returns a tuple made of:

(Number ) –

false if the value couldn't be returned, true otherwise.

value (Number ) –

false if the value couldn't be returned, true otherwise.

Gst.ControlSource.control_source_get_value

def Gst.ControlSource.control_source_get_value (self, timestamp):
    #python wrapper for 'gst_control_source_get_value'

Gets the value for this Gst.ControlSource at a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource object

timestamp (int) –

the time for which the value should be returned

Returns a tuple made of:

(bool ) –

False if the value couldn't be returned, True otherwise.

value (float ) –

False if the value couldn't be returned, True otherwise.

gst_control_source_get_value_array

gboolean
gst_control_source_get_value_array (GstControlSource * self,
                                    GstClockTime timestamp,
                                    GstClockTime interval,
                                    guint n_values,
                                    gdouble * values)

Gets an array of values for for this GstControlSource. Values that are undefined contain NANs.

Parameters:

self –

the GstControlSource object

timestamp –

the first timestamp

interval –

the time steps

n_values –

the number of values to fetch

values ( [arraylength=n_values]) –

array to put control-values in

Returns –

TRUE if the given array could be filled, FALSE otherwise

Gst.ControlSource.prototype.control_source_get_value_array

function Gst.ControlSource.prototype.control_source_get_value_array(timestamp: Number, interval: Number, n_values: Number, values: [ Number ]): {
    // javascript wrapper for 'gst_control_source_get_value_array'
}

Gets an array of values for for this Gst.ControlSource. Values that are undefined contain NANs.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource object

timestamp (Number) –

the first timestamp

interval (Number) –

the time steps

n_values (Number) –

the number of values to fetch

values ([ Number ]) –

array to put control-values in

Returns (Number) –

true if the given array could be filled, false otherwise

Gst.ControlSource.control_source_get_value_array

def Gst.ControlSource.control_source_get_value_array (self, timestamp, interval, n_values, values):
    #python wrapper for 'gst_control_source_get_value_array'

Gets an array of values for for this Gst.ControlSource. Values that are undefined contain NANs.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource object

timestamp (int) –

the first timestamp

interval (int) –

the time steps

n_values (int) –

the number of values to fetch

values ([ float ]) –

array to put control-values in

Returns (bool) –

True if the given array could be filled, False otherwise

GstTimedValue

Structure for storing a timestamp and a value.

Members

timestamp (GstClockTime) –

timestamp of the value change

value (gdouble) –

the corresponding value

Gst.TimedValue

Structure for storing a timestamp and a value.

Members

timestamp (Number) –

timestamp of the value change

value (Number) –

the corresponding value

Gst.TimedValue

Structure for storing a timestamp and a value.

Members

timestamp (int) –

timestamp of the value change

value (float) –

the corresponding value

Constants

GST_TYPE_CONTROL_SOURCE

#define GST_TYPE_CONTROL_SOURCE \
  (gst_control_source_get_type())

Callbacks

GstControlSourceGetValue

gboolean
(*GstControlSourceGetValue) (GstControlSource * self,
                             GstClockTime timestamp,
                             gdouble * value)

Function for returning a value for a given timestamp.

Parameters:

self –

the GstControlSource instance

timestamp –

timestamp for which a value should be calculated

value –

a value which will be set to the result.

Returns –

TRUE if the value was successfully calculated.

Gst.ControlSourceGetValue

function Gst.ControlSourceGetValue(self: Gst.ControlSource, timestamp: Number, value: Number): {
    // javascript wrapper for 'GstControlSourceGetValue'
}

Function for returning a value for a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource instance

timestamp (Number) –

timestamp for which a value should be calculated

value (Number) –

a value which will be set to the result.

Returns (Number) –

true if the value was successfully calculated.

Gst.ControlSourceGetValue

def Gst.ControlSourceGetValue (self, timestamp, value):
    #python wrapper for 'GstControlSourceGetValue'

Function for returning a value for a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource instance

timestamp (int) –

timestamp for which a value should be calculated

value (float) –

a value which will be set to the result.

Returns (bool) –

True if the value was successfully calculated.

GstControlSourceGetValueArray

gboolean
(*GstControlSourceGetValueArray) (GstControlSource * self,
                                  GstClockTime timestamp,
                                  GstClockTime interval,
                                  guint n_values,
                                  gdouble * values)

Function for returning an array of values starting at a given timestamp.

Parameters:

self –

the GstControlSource instance

timestamp –

timestamp for which a value should be calculated

interval –

the time spacing between subsequent values

n_values –

the number of values

values –

array to put control-values in

Returns –

TRUE if the values were successfully calculated.

Gst.ControlSourceGetValueArray

function Gst.ControlSourceGetValueArray(self: Gst.ControlSource, timestamp: Number, interval: Number, n_values: Number, values: Number): {
    // javascript wrapper for 'GstControlSourceGetValueArray'
}

Function for returning an array of values starting at a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource instance

timestamp (Number) –

timestamp for which a value should be calculated

interval (Number) –

the time spacing between subsequent values

n_values (Number) –

the number of values

values (Number) –

array to put control-values in

Returns (Number) –

true if the values were successfully calculated.

Gst.ControlSourceGetValueArray

def Gst.ControlSourceGetValueArray (self, timestamp, interval, n_values, values):
    #python wrapper for 'GstControlSourceGetValueArray'

Function for returning an array of values starting at a given timestamp.

Parameters:

self (Gst.ControlSource) –

the Gst.ControlSource instance

timestamp (int) –

timestamp for which a value should be calculated

interval (int) –

the time spacing between subsequent values

n_values (int) –

the number of values

values (float) –

array to put control-values in

Returns (bool) –

True if the values were successfully calculated.

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