Load a set of fonts in the fontmap that can be used to render a font matching desc.
the gstreamer.Context the font will be used with
a PangoFontDescription describing the font to load
a PangoLanguage the fonts will be used for
the newly allocated PangoFontset loaded, or NULL if no font matched.
Load a set of fonts in the fontmap that can be used to render a font matching desc.