gboolean a_babel_convert( VikTrwLayer *vt, const char *babelargs, BabelStatusFunc cb, gpointer user_data, gpointer options );
gboolean a_babel_convert_from( VikTrwLayer *vt, const char *babelargs, const char *file, BabelStatusFunc cb, gpointer user_data, gpointer options );
gboolean a_babel_convert_from_shellcommand ( VikTrwLayer *vt, const char *input_cmd, const char *input_file_type, BabelStatusFunc cb, gpointer user_data, gpointer options );
gboolean a_babel_convert( VikTrwLayer *vt, const char *babelargs, BabelStatusFunc cb, gpointer user_data, gpointer options );
gboolean a_babel_convert_from( VikTrwLayer *vt, const char *babelargs, const char *file, BabelStatusFunc cb, gpointer user_data, gpointer options );
gboolean a_babel_convert_from_shellcommand ( VikTrwLayer *vt, const char *input_cmd, const char *input_file_type, BabelStatusFunc cb, gpointer user_data, gpointer options );