GstPreset

GstPreset — helper interface for element presets

Synopsis

gchar **            gst_preset_get_preset_names         (GstPreset *self);
gboolean            gst_preset_load_preset              (GstPreset *self,
                                                         const gchar *name);
gboolean            gst_preset_save_preset              (GstPreset *self,
                                                         const gchar *name);
gboolean            gst_preset_rename_preset            (GstPreset *self,
                                                         const gchar *old_name,
                                                         const gchar *new_name);
gboolean            gst_preset_delete_preset            (GstPreset *self,
                                                         const gchar *name);
gboolean            gst_preset_set_meta                 (GstPreset *self,
                                                         const gchar *name,
                                                         const gchar *tag,
                                                         const gchar *value);
gboolean            gst_preset_get_meta                 (GstPreset *self,
                                                         const gchar *name,
                                                         const gchar *tag,
                                                         gchar **value);

Description

This interface offers methods to query and manipulate parameter preset sets. A preset is a bunch of property settings, together with meta data and a name. The name of a preset serves as key for subsequent method calls to manipulate single presets. All instances of one type will share the list of presets. The list is created on demand, if presets are not used, the list is not created.

The interface comes with a default implementation that serves most plugins. Wrapper plugins will override most methods to implement support for the native preset format of those wrapped plugins. One method that is useful to be overridden is gst_preset_get_property_names(). With that one can control which properties are saved and in which order.

Details

gst_preset_get_preset_names ()

gchar **            gst_preset_get_preset_names         (GstPreset *self);

Get a copy of preset names as a NULL terminated string array. Free with g_strfreev() wen done.

self :

a GObject that implements GstPreset

Returns :

list with names

gst_preset_load_preset ()

gboolean            gst_preset_load_preset              (GstPreset *self,
                                                         const gchar *name);

Load the given preset.

self :

a GObject that implements GstPreset

name :

preset name to load

Returns :

TRUE for success, FALSE if e.g. there is no preset with that name

gst_preset_save_preset ()

gboolean            gst_preset_save_preset              (GstPreset *self,
                                                         const gchar *name);

Save the current preset under the given name. If there is already a preset by this name it will be overwritten.

self :

a GObject that implements GstPreset

name :

preset name to save

Returns :

TRUE for success, FALSE

gst_preset_rename_preset ()

gboolean            gst_preset_rename_preset            (GstPreset *self,
                                                         const gchar *old_name,
                                                         const gchar *new_name);

Renames a preset. If there is already a preset by the new_name it will be overwritten.

self :

a GObject that implements GstPreset

old_name :

current preset name

new_name :

new preset name

Returns :

TRUE for success, FALSE if e.g. there is no preset with old_name

gst_preset_delete_preset ()

gboolean            gst_preset_delete_preset            (GstPreset *self,
                                                         const gchar *name);

Delete the given preset.

self :

a GObject that implements GstPreset

name :

preset name to remove

Returns :

TRUE for success, FALSE if e.g. there is no preset with that name

gst_preset_set_meta ()

gboolean            gst_preset_set_meta                 (GstPreset *self,
                                                         const gchar *name,
                                                         const gchar *tag,
                                                         const gchar *value);

Sets a new value for an existing meta data item or adds a new item. Meta data tag names can be something like e.g. "comment". Supplying NULL for the value will unset an existing value.

self :

a GObject that implements GstPreset

name :

preset name

tag :

meta data item name

value :

new value

Returns :

TRUE for success, FALSE if e.g. there is no preset with that name

gst_preset_get_meta ()

gboolean            gst_preset_get_meta                 (GstPreset *self,
                                                         const gchar *name,
                                                         const gchar *tag,
                                                         gchar **value);

Gets the value for an existing meta data tag. Meta data tag names can be something like e.g. "comment". Returned values need to be released when done.

self :

a GObject that implements GstPreset

name :

preset name

tag :

meta data item name

value :

value

Returns :

TRUE for success, FALSE if e.g. there is no preset with that name or no value for the given tag