GStreamer 1.0 Core Reference Manual: GstControlBinding

## GstControlBinding GstControlBinding — attachment for control source sources |

## Functions

gboolean | gst_control_binding_sync_values ()
GValue * | gst_control_binding_get_value ()
gboolean | gst_control_binding_get_value_array ()
gboolean | gst_control_binding_get_g_value_array ()
void | gst_control_binding_set_disabled ()
gboolean | gst_control_binding_is_disabled ()

## Properties

gchar * | name | Read / Write / Construct Only
GstObject * | object | Read / Write / Construct Only

## Types and Values

struct | GstControlBinding
struct | GstControlBindingClass

## Object Hierarchy

        GObject
        ╰── GInitiallyUnowned
            ╰── GstObject
                ╰── GstControlBinding

## Includes

    #include <gst/gst.h>

## Description

A base class for value mapping objects that attaches control sources to gobject properties. Such an object is taking one or more GstControlSource instances, combines them and maps the resulting value to the type and value range of the bound property.

## Functions

### gst_control_binding_sync_values ()

    gboolean
    gst_control_binding_sync_values (GstControlBinding *binding,
                                     GstObject *object,
                                     GstClockTime timestamp,
                                     GstClockTime last_sync);

Sets the property of the `object` , according to the GstControlSources that 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.

#### Parameters

binding | the control binding |
object | the object that has controlled properties |
timestamp | the time that should be processed |
last_sync | the last time this was called |

#### Returns

`TRUE` if the controller value could be applied to the object property, `FALSE` otherwise

### gst_control_binding_get_value ()

    GValue *
    gst_control_binding_get_value (GstControlBinding *binding,
                                   GstClockTime timestamp);

Gets the value for the given controlled property at the requested time.

#### Parameters

binding | the control binding |
timestamp | the time the control-change should be read from |

#### Returns

the GValue of the property at the given time, or `NULL` if the property isn't controlled.

### gst_control_binding_get_value_array ()

    gboolean
    gst_control_binding_get_value_array (GstControlBinding *binding,
                                         GstClockTime timestamp,
                                         GstClockTime interval,
                                         guint n_values,
                                         gpointer 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_control_binding_get_g_value_array()` returns the array as GValues and is more suitable for bindings.

#### Parameters

binding | the control binding |
timestamp | the time that should be processed |
interval | the time spacing between subsequent values |
n_values | the number of values |
values | array to put control-values in |

#### Returns

`TRUE` if the given array could be filled, `FALSE` otherwise

### gst_control_binding_get_g_value_array ()

    gboolean
    gst_control_binding_get_g_value_array (GstControlBinding *binding,
                                           GstClockTime timestamp,
                                           GstClockTime interval,
                                           guint n_values,
                                           GValue *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.

#### Parameters

binding | the control binding |
timestamp | the time that should be processed |
interval | the time spacing between subsequent values |
n_values | the number of values |
values | array to put control-values in |

#### Returns

`TRUE` if the given array could be filled, `FALSE` otherwise

### gst_control_binding_set_disabled ()

    void
    gst_control_binding_set_disabled (GstControlBinding *binding,
                                      gboolean disabled);

This function is used to disable a control binding for some time, i.e. `gst_object_sync_values()` will do nothing.

#### Parameters

binding | the control binding |
disabled | boolean that specifies whether to disable the controller or not. |

### gst_control_binding_is_disabled ()

    gboolean
    gst_control_binding_is_disabled (GstControlBinding *binding);

Check if the control binding is disabled.

#### Parameters

binding | the control binding |

#### Returns

`TRUE` if the binding is inactive

## Types and Values

### struct GstControlBinding

    struct GstControlBinding {
      gchar *name;
      GParamSpec *pspec;
    };

The instance structure of GstControlBinding.

#### Members

gchar *`name`; | name of the property of this binding |
GParamSpec *`pspec`; | GParamSpec for this property |

### struct GstControlBindingClass

    struct GstControlBindingClass {
      GstObjectClass parent_class;

      gboolean (* sync_values) (GstControlBinding *binding, GstObject *object, GstClockTime timestamp, GstClockTime last_sync);
      GValue * (* get_value) (GstControlBinding *binding, GstClockTime timestamp);
      gboolean (* get_value_array) (GstControlBinding *binding, GstClockTime timestamp,GstClockTime interval, guint n_values, gpointer values);
      gboolean (* get_g_value_array) (GstControlBinding *binding, GstClockTime timestamp,GstClockTime interval, guint n_values, GValue *values);
    };

The class structure of GstControlBinding.

#### Members

GstObjectClass `parent_class`; | Parent class |
`sync_values` () | implementation for updating the target values |
`get_value` () | implementation to fetch a single control-value |
`get_value_array` () | implementation to fetch a series of control-values |
`get_g_value_array` () | implementation to fetch a series of control-values as g_values |

## Property Details

### The `“name”` property

      “name”                     gchar *

The name of the property.

Flags: Read / Write / Construct Only

Default value: NULL

### The `“object”` property

      “object”                   GstObject *

The object of the property.

Flags: Read / Write / Construct Only